try to change between these four options and see the result
debug.composition.type=cpu or debug.composition.type=gpu or debug.composition.type=mdp or debug.composition.type=c2d
http://rootzwiki.com/topic/18843-releasealpha2-cyanogenmod-9-touchpad/page__st__110
Yes I've tried all 4 options. CPU and GPU fixed the problems I'm having at the cost of slower performance. C2D gives the best performance but gives me the same rendering problems as MDP.