i had more problems using whdload with my A600, than with the A4000 CyberstormPPC i'm now using. most of the problems where however due to little ram on the A600.
here's a few games i've run flawlessly in the last few days:
4x4 offroad racing, alcatraz, adventures of robin hood, all new world of lemmings.
using A4000 CyberstormPPC with OS 3.9, updated libs and drivers, whdload 16.9 registered.