Very common problem, the only way to truly fix it is an overhaul, unfortunately.
http://www.tripleedgeperformance.com...-Problems.html
These guys know their stuff, and this info has helped me out quite a bit when I first started having issues. Mine's been doing that for years, still does it occasionally. I know I need to dig in there and do a proper overhaul, but it's still going, so I'll take it.
My advice is set up some form of fall-back plan and be prepared to get the trans fixed, but continue to drive it until it does break/becomes un-driveable. That's what I'm doing. There's quite a few options for a back-up plan, all depending on how mechanically inclined you are.
