I would check the torque converter clutch solenoid. I'm sorry but I can't locate it for you in my database, but when you find it, if you disconnect it momentarily (don't DRIVE like that) and this cures the problem, then that's your answer. What's happening is similar to you coming to a stop in gear with a manual transmission car. The torque converter direct lockup is not disconnecting, hence you stall in D but not in L, because the lockup isn't working in L.
Just a guess.