Godaddy wordpress lots of problem !!! Please Help

Since I installed wordpress there is not a single day without any problem. Most recently I am having the most serious problem consistently. I am getting HTTP 500 Internal Server Error very randomly. I get this error both in admin and front end. I tried so many things (uninstalled plugins/repaired database) to try to get rid of this. Unfortunately nothing good happened.

I am just a beginner so I could not sort out what exactly is causing this problem. I asked godaddy support, but as usual they replied with readymade kind of answer (we don’t support third party content..blah blah blah). There are lots of developer in this forum. Would anybody please kindly help me to resolve this issue? What would be the most common reason behind this? Is there any plugin/script to check and fix this kinda errors.

Thank you very much in advance.

Here is the error log from my server:

[Mon Jun 28 02:55:27 2010] [error] [client 202.166.200.133] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/index.php
[Mon Jun 28 03:12:28 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/index.php
[Mon Jun 28 04:01:02 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-login.php
[Mon Jun 28 04:01:32 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-login.php
[Mon Jun 28 04:02:02 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-admin/profile.php
[Mon Jun 28 04:02:32 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-admin/profile.php
[Mon Jun 28 06:25:44 2010] [error] [client 82.232.55.48] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/index.php
[Mon Jun 28 20:56:26 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-login.php
[Mon Jun 28 21:10:27 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-admin/admin-ajax.php
[Mon Jun 28 22:14:01 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/index.php
[Mon Jun 28 22:49:33 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/index.php
[Mon Jun 28 23:04:04 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-admin/index.php
[Mon Jun 28 23:19:35 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-content/plugins/nextgen-gallery/admin/upload.php
[Mon Jun 28 23:20:06 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/wp-content/plugins/nextgen-gallery/admin/upload.php
[Mon Jun 28 23:42:07 2010] [error] [client 202.166.212.219] Premature end of script headers: /var/chroot/home/content/k/a/t/kathamitho/html/index.php
[Mon Jun 28 23:47:04 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:07 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:10 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:14 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:17 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:17 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:20 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:21 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:21 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:21 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:21 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:21 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:22 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:22 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:23 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:24 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:47:24 2010] [alert] [client 202.166.212.219] /var/chroot/home/content/k/a/t/kathamitho/html/.htaccess: Invalid command ‘1.’, perhaps mis-spelled or defined by a module not included in the server configuration
[Mon Jun 28 23:48:07 2010] [error] [client 202.166.212.219] (104)Connection reset by peer: FastCGI: comm with server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5” aborted: read failed
[Mon Jun 28 23:48:07 2010] [error] [client 202.166.212.219] FastCGI: incomplete headers (0 bytes) received from server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5”
[Mon Jun 28 23:51:37 2010] [error] [client 74.63.112.137] (104)Connection reset by peer: FastCGI: comm with server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5” aborted: read failed
[Mon Jun 28 23:51:37 2010] [error] [client 74.63.112.137] FastCGI: incomplete headers (0 bytes) received from server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5”
[Mon Jun 28 23:55:08 2010] [error] [client 74.63.112.137] (104)Connection reset by peer: FastCGI: comm with server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5” aborted: read failed
[Mon Jun 28 23:55:08 2010] [error] [client 74.63.112.137] FastCGI: incomplete headers (0 bytes) received from server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5”
[Tue Jun 29 01:15:13 2010] [error] [client 116.90.224.115] (104)Connection reset by peer: FastCGI: comm with server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5” aborted: read failed
[Tue Jun 29 01:15:13 2010] [error] [client 116.90.224.115] FastCGI: incomplete headers (0 bytes) received from server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5”
[Tue Jun 29 02:14:47 2010] [error] [client 202.166.212.219] (104)Connection reset by peer: FastCGI: comm with server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5” aborted: read failed
[Tue Jun 29 02:14:47 2010] [error] [client 202.166.212.219] FastCGI: incomplete headers (0 bytes) received from server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5”
[Tue Jun 29 02:15:17 2010] [error] [client 202.166.212.219] (104)Connection reset by peer: FastCGI: comm with server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5” aborted: read failed
[Tue Jun 29 02:15:17 2010] [error] [client 202.166.212.219] FastCGI: incomplete headers (0 bytes) received from server “/var/chroot/home/content/k/a/t/kathamitho/html-x-httpd-php5”