1995 Saturn SC1 Car lurching when in drive

my son has a 1995 Saturn SC with automatic transmission. Lately, when the car is warm, in drive with foot on the brake, the car is lurching. Does not do it in reverse or other gears. You can see the tires trying to move and you can see the tach idling up, then down. Seems like the transmission does not fully disengage once the car is brought to a stop or maybe it does but then tries to reengage. Cannot seem to locate the problem. Any suggestions? Bad tranny or is there a vacuum or electrical answer? Does the computer control what the transmission is supposed to do? What if I disconnect the battery and reconnect? Maybe computer has bad info?

Thanks.