Somebody needs to try the "Search" button above... just kidding, but I saw your other question was answered with links too.
http://www.sportsmobileforum.com/vie...atlas+pops+out
I didn't re-read the thread, don't know if it was ever resolved but there are a lot of good suggestions (and some that I made) in that thread. If that doesn't cover it I'm sure we'll all be glad to make more bad suggestions for your particular case.
FWIW, I don't think the fluid has anything to do with it. Among other things the atlas in my Jeep ran dry (blew all the fluid out on the Interstate) and it drives just fine, even in low with next to no fluid. True I haven't taken it out of the driveway since and I haven't had a chance to determine what failed, but popping out of gear is not a problem.