1990 Oldsmobile Cutlass stalls with A/C engaged and engine

I bought this car as my new work car. It has an intermittant issue with high idle and occasionally stalls when put into park. The high idle issue seems to only occur when the engine is cold (i.E, sitting in the parking lot during my work night, or overnight at the house) and the car is started with A/C on. Even when it occurs, after driving even two miles, the issue cannot be duplicated. The stalling also occured when driven under two miles and the A/C was engaged. Typically the fan speed has been on high when these issues occur. The car has been to the local GM dealer for several weeks and they were unable to duplicate the situation. I had a check engine light the first time this happened while the idle was running away, but it went out once I de-selected the A/C off and it has not come on since then. No codes set. The issue does not occur if the car is started with A/C not on. It is quite intermittant. The dealer tried to duplicate it six or seven times with no luck. It has happened to me three or four times in the month that I have used the car (though it mostly has been in the shop for repair/update work). The car seems to run perfectly fine otherwise and A/C also works good. When I bought the car, I had the dealer check for codes and the only thing that showed at that time was an old TPS voltage high code, but they said that it was really old with nothing recent.