Last night, I drove my daughter's '93 Accord LX Automatic about 40 miles on
the highway and in traffic.  It ran fine.  I stopped at a store, restarted
the car after it had sat for a few minutes, and it was sluggish... looked
down and the "D" indicator was flashing (indicating a problem). Pulled out
on the street and drove it about 1.5 miles to the next light. It seemed to
slip the torque converter a lot and was sluggish starting up (like it was
stuck in a higher gear). (I had just checked the fluid level a week before,
and it was fairly new fluid too.)

Stopped at the light, put it in Neutral, stopped the motor.  Restarted it 20
seconds later when the light turned green and it was fine. No flashing "D".
No sluggishness.

Any ideas? The problem almost seems electrical... but the Hayes manual I
have for the car doesn't say much about the tranny.  Why did it go away once
I stopped and turned things off?

TIA