Under mild acceleration, from dead stop, the trans shifts then decides it has shifted too early and immediately downshifts back to first. If I back off the throttle when the upshift occurs I can keep it from downshifting but the RPM's seem awfully low.

Under hard acceleration shifting seems to work normally although unpredictably there will be a slight hesitation as 2nd gear "locks" in.

Under mildest of acceleration shifting works normally as well.

 

Sounds like the TV cable may need adjustment. Check out the link below:
700R4/2004R TV Cable Adjustment Instructions

 

Thanks. Next time I see her, 100+ miles away at the moment, I'll give that a shot and report back.