In any video setting other than 4:3 (single head) display, the chat window does not appear on screen. If in triple head mode (Matrox THTG) @3072x768 (or any res for that matter), the chat window does not appear at all when pressing "/", although if I type and hit "enter" it will still display the message. This isn't a big deal until you're in PvP and don't know what channel you're typing to...
I searched the forums for a while and didn't see this anywhere, so I'd be curious to know if others with triple head setups are having this issue.