I recently changed hosting providers (large host to hosting myself). I exported my wordpress MySQL database and imported it into my MySQL instance, then installed WordPress on my server (iMac running OSX 10.4.10). The blog works fine, I can post, but that's about it. If you click on any link that takes you to a specific post, or click on any category or archive link, an error of "page not found" comes up.
Before I changed hosts, the blog was working perfectly.
If you want to see it for yourself, you can visit my blog (http://nickmelchi.com/blog)
I searched google and the forums, but only came up with a few unrelated topics.