page not found when creating content

I was updating the site when suddenly I got Page not Found pages and 403.shtml not found error reports when i tried submitting new story. A few minutes before that I was able to create story. Funny thing is I'm able to create event, but when I create story I get the problems mentioned above. I'm using 4.7.3, PHP version 4.4.2, Mysql 4.1.21. I really need the help thanks.