Problem after modification of a table

Hello,

I have installed on a local computer WordPress 2.9.2, it’s working fine and after I upload it to my web account, it is still working fine.

Now, I want to update some data in the table wp_options (on the web account), the siteurl because as it was installed locally, the url was with localhost/mysubfolder
If I modify it with real URL, then after that I receive the following message when I try to login to the admin panel of WordPress:
“Warning: Cannot modify header information – headers already sent by (output started at /home/theimscr/public_html/testwp/wp-config.php:1) in /home/theimscr/public_html/testwp/wp-login.php on line 302

Warning: Cannot modify header information – headers already sent by (output started at /home/theimscr/public_html/testwp/wp-config.php:1) in /home/theimscr/public_html/testwp/wp-login.php on line 314
Mon blog WPT”

The modification has been made through phpMyAdmin and not by editing a file with Notepad or something else. I’m using cPanel v. 11

Thanks for your help!

David