My thanks to everyone for their comments and help. This community is an excellent source of help and advice. I cant remember the last time I visited the cesspool forums at the WoW main site. If I need to know anything I usually check here first.
It turns out that my damage meter had become corrupted somehow and was showing the same data for incoming as well as outgoing so the critical hit thing was false data. I reloaded a fresh version and we made numerous runs at Heroic Gundrak and Draktheron Keep last night, which did show 0 crits, but nonetheless it didnt go so well as after 4 separate runs to the repair man at 0% armor led us to decide that we are gonna hold off for a bit until we straighten all our gear out.