This topic has many search results.
However from all my reading, I have still not found a solution. The other day I realized I had jumped the gun and decided to change my domain name. I called my host and the only way to change the name was to purchase another one. Cheap enough, so i did it. That's when everything went wrong. They made all the changes and everything seemed fine. I could login to my wp cp from either domain. Also going to either url resulted in a viewable and functioning site. The only thing I changed were the paths to all my media inside all my posts. Then I logged out. The next morning I couldn't login no matter which url I used. I called support and they said they could fix it. A couple of hours later, nothing had been fixed. I went to wordpress to search the forums and found a couple of posts describing how to change some code via ftp. It worked to get me in. Or maybe it didn't because just as I got back into the cp, I received an email from support stating that the tech had fixed the problem and that he could login and I should be able to as well. He also stated that he had to revert back to the default theme (twenty-ten) and that he also deactivated all my plugins. As soon as I read the email, I refreshed a browser that was viewing the site and the site failed to load. I went into appearance and found that neither themes were activated. I activated the one I prefer (Easel) and the site came back up with all defaults. I reactivated all my plugs and everything looked fine. I went to change a page and found that I "had no permissions to preview drafts". I tried a new test "post" and when I tried to preview it, the result was "file not found" error. The error also stated that should contact "cgiadmin@myhost" to correct the issue.
I called support back and have heard nothing for perhaps 6 hours. I really feel that the transfer is the issue. But I don't know enough to know for sure.
Any help would be appreciated.