WordPress 2.0 came out a little while ago. I’m installing it on a new site and ran into a problem on the install step.
The fix is to comment out line 38:
Line 38 in wp-settings.php is a “fix” for (quote):
// Fix for PHP as CGI hosts that set SCRIPT_FILENAME to something ending in php.cgi for all requests
Is this the case with your server?
Note: I’m running WordPress on a Windows 2003 server with MySQL on the same box. That might have been the source of the error.