OK, WOW is out to drive me crazy. The particular quest was "The Fel and the Furious (H)". I just checked it, and both Live and Test tabs have the same posts. However, my post on the Live tabe, asking why I couldn't activate the consoles (I know now, dismiss pet) wasn't there. Just before I posted this question, it was there, and was the only post there. I'll just consider it the usual computer system flakiness.
However, the basic question still remains- what is the difference between the Live and the Test tabs?