hi nelson:

wasting of the butt (glutes): is there any way to prevent this? of course, heavy squats, stiff legged dead lifts, butt machines, etc have some effect. but over time, have u noticed butt-wasting? has it been pretty much irreversable?

Butt wasting is one of the most common features of lipoatrophy (fat loss). Like you said, working out may keep a muscular butt but the fat loss still occurs in those taking nucleosides like Zerit or AZT. Aging also has that bad side effect.

There are hard silicone implants and injectable products like Bio-Alcamid. Both options are expensive. The hard implant requires a painful recovery. I would not recommend silicone injections in the butt (although I have seen several HIV positive men do this, some with good results and some with horrible infections and auto-immune response)