Looks like I wasn't the only one... a quick glace at the Apple support forums shows many users having issues with non-Apple DVI LCD monitors (usually 20" and higher). The problem seems to be the ATI drivers not allowing "alternate DVI mode" (this option is available in Windows drivers).
Looks like we have found the first "major" problem with the Mini... too bad it involves monitor compatibility since som many "switchers" would be coming BYOD.
Apple Discussion Forums: Mac Mini Displays