I had a blog, which was fine. I then upgraded my Server to PHP5 and MySQL5. Then the blog stopped working: I can't edit posts... I keep getting 404 errors in pop-up windows. If I make a new post, and try to click on 'html' (to view the source), or put a link on some word, I get pop-ups with 404 error pages.
If I make a new wordpress installation someplace else it works perfectly. I tried removing my own installation, and then install a fresh one. This worked okay. Then I imported my DB (without the options table!) and the same error occurs.
Please help! I'm desperate!!!!!