Numerous WP Problems

I seem to have a number of problems with WordPress blog. #1 my Pages do not work leading to the ‘404 Error’ page, #2 .htaccess file has the tendency revert to ‘blank’ state, #3 when I create a new category, it and any post in it give me the same 404 Error that #1 does.

I post all of these because I have the feeling that they’re are all related. Any ideas?