Umm I think the server might be possessed my an evil spirit. We have called in an exorcist.
Actually it is probably caused by something like the difference btwn the PHP accelerator script running things vs the CGI script. I am upgrading to V 6.5.0 soon and that may well take care of that happening.
Is this happening to anyone else? Let me know because I will take it to the manufactures of UBB.