[boostedc10]

I would go with Hart's first post and log some data. Without any data we can only speculate what could be going on. In Hart's second link from HP Tuners you need to at least log the current gear, force motor current , tcc mode and tcc slip. These PID'S with the standard engine PID'S should give you a good idea what is going on.

I also like to run a manual gauge to see what the actual pressure is doing when the problem occurs.

The pressure control solenoid does just that, controls the pressure in the trans for shift quality wear and acts like an electronic version of a kickdown cable.