1997 Dodge Avenger Trans dropping out of OD to 2nd gear

My Avenger occasionally drops out of 4th/OD to 2nd gear, and the check engine light comes on & stays on.

The codes that show up are:
P0700 Transmission Control System Malfunction
P0750 Shift Solenoid A Malfunction

This problem has happened a total of 3 times so far, with two of those times happening just before Christmas, and the other just today.

I did a trans fluid & filter change using the +4 fluid, after the first incident, and changed the Solenoid pack after the second time.

When this happens, I can turn the car off while rolling (or stopped) & restart, and the trans will shift normal - even with the check engine light on solid.

The solenoid pack is a new part from Borg Warner, and since it is doing the exact same thing, I have to say the problem is somewhere else. I just ordered a TPS for the car on the off chance that there might be a dead spot on the film, (very small possibility as this type of sensor tests into the 1 million cycle range - but still possible).

I figured for $30.00, it was worth a shot. The only other part I can think of that could be causing this is the computer, which is $300 for a rebuilt unit.

Have you run into this before? Any ideas as to what might be causing it?

This is currently my daily driver, and it goes about 80 miles a day - 5 days, so I need it to be reliable. It has been great for over a year. Trying to get it to go some more.

Ironically, I used to work at a transmission shop in Flint, Michigan, but that was before all the electronic shift solenoids came into the picture. Worst electrical issue we dealt with - LU solenoids crapping out - no big deal.

Any advice would be very much appreciated.