When trying to update the General Settings, I get an HTTP 500: Internal Server Error. (Whether I select 'rebuild' or not.)

This function used to work, and all other administrative features still do work, but since recently, I can't use this feature anymore. (We also had a problem with the lastnumber.file, which caused threads to be overwritten; but I'm not sure if these two problems are related.)

The version number is 5.45c, running under WinNT, and it's located at http://www.racernetwork.com/ubb/cgi-bin/Ultimate.cgi

I tried to activate the 'print "HTTP/1.0 200 OKn";' line in cpanel2.cgi, as suggested for IIS systems, but it didn't make a difference.