transmission shudder

after a long highway drive, exit ramp to a stop, sit idle for the duration of the light, i give it throttle and feel a light stumble or slip. happens one more time at the next light, but then fine. This has happened after the same long drive before, but even an hour or so drive doesnt produce this.

i read and learned that the lock up solenoid valve can fail to release after long high transmission temps. Is this true? reading rave shows this lockup valve on true fault will illuminate the MIL, which it hasnt done, yet.

Any other ideas as to what may cause this slip, stumble, or whatever it is? Feels almost like an engine mis or right before a stall, but I don't drop RPM's - just feel a shotty shift

04 w/ 38k

possible overfilled transmission when the dealer serviced at 30k?

Should I call the dealer even though its out of warranty or just proceed with the check myself? I am starting to think it is something the dealer did

even if it has only happened after a long drive? I can see that being the case when it is always shuddering, but other than the above symptom it never happens