Hmm, after browsing that thread it could be an
EDID issue*. I'll try the new HDMI cable when it comes in first. If it's still a problem I'll try the HDMION utility. If that solves it, I may still go ahead and put the other graphics card in anyway. HDMION will require a keyboard press every time we switch inputs to the computer. I'd rather not have to reach for the keyboard every time.
*Might also explain the weird line of pixels that occasionally appears at the top of the screen while viewing the PC and persists across TV inputs until the tv is turned off then on. Sigh, don't I deal with enough crap about poor standardization of handshaking protocols at work?!