Thanks, I got the PM. Yeah, it's just a warning, so there's nothing to panic about. It's still weird, though.
Could you do me a favor? Grab your copy of the UBB.classic zip file, and look inside the tools folder. There'll be a file named ubbclassic_test.cgi. Upload it to your site, and run it.
The very first test at the top will look like:
Perl Version Check:
5.008003 (ActiveState build 809)
Though the numbers will be different. Can you copy and paste that information here? When done, delete the file from your server.