Logout problem

Since I upgraded, I can no longer logout from the wp-admin. When I try it returns this error: Can’t load wp-config.php (located in “/home/changedthispart”). You must put this plugin in your plugins directory (“/wordpress/wp-content/plugins/”). I have reuploaded wp-login.php and that made no difference.

The site was originally 1.5, then 2.0, then 2.1.1 then 2.1.2 if that makes any difference.

Another site I upgraded directly from 1.5 to 2.1.2 is having the same problem. It worked fine under 1.5 2 days ago.

The tricky part is I have a development site running 2.1.2 (original installed 2.0) that logs out just fine. I compared the config files between the 2 and made them identical. It didn’t fix the broken site.

Any help much appreciated.