Thanks Huli. 
I am kinda a “basket case”. My docs normally treat me like i am made of porcelain. (Not really understanding that the high heart rate/pain level are tied together and, for me at least, NORMAL.) I have no problem doing something, provided the return is greater than the downside/pain.
The instructor/class leader was aware of my circumstances. I think the “float effect” you mentioned is pretty dead on. For most, the transition from semi-weightlessness back to full weight is rather quick and gotten past without too much difficulty. A few steps, five minutes or less, and they are back to “normal’. It may be that my transition is just so much harsher that it is difficult to move fully back to “normal”. (Bone-crushing, stabbing pain at every slight movement.) Also, after the exercise, my muscles are ?tired?, so the fine control I constantly maintain is that much harder to achieve. Agony results.
Anyhow, i don’t want to make this whole thing a thread on my pain issues. (Long and boring.) I’ve always enjoyed the way tai Chi looks, and learning it slowly probably wouldn’t hurt me. 
Now that i have the webz back, i shall go out looking at what everyone has given me. Thanks.
