BAGreenSVT,
It sounds like a control problem to me also. When it does shift it doesn't seem to slip. Most of the time it just won't shift without letting up on the accelerator. I do hope there is someone out there who knows the answer. If it does need a new transaxle, my son-in-law and I will probably do it ourselves but, I do want to know what the problem is BEFORE we just start throwing parts at it. If you get further information please post it. I will do likewise.
THANKS!