Yet another window positioning problem... occasionally won't go up

Hey team, My 996.2 has an intermittent problem where the passenger window seems to forget its position memory. Once in a dozen times, when you turn off the car and the passenger exits the vehicle, upon closing the door the window will roll down 6". After that, you can still operate the window both up and down just fine, but if you go all the way down, sometimes it will not go back up again. Here's an itemized list of symptoms: When the window is all the way down, pressing the switch UP results in a relay clicking sound, but no motor noise whatsoever. Pressing the switch DOWN at that time results in relay clicking sound AND a small motor grunt, like it's confirming it's all the way down. When stuck down, if you press and release UP over and over again, the relay always clicks but most of the time there is no motor engagement. Eventually it will "catch" and the motor starts and the window goes up, either all the way or until you release the button. It only seems to be a problem if you go all the way down first. In other words, if you roll the window down 10", then stop, then down 2" more, then stop, then 8" up, then stop, or any other combination EXCEPT full down, the UP button always works. But if you go all the way down, 20% of the time (estimating) it gets stuck again and will not go up. I've tried the various "known" window memory reset procedures, with no lasting success. Full down, hold 10 sec, full up, hold 10 sec, full down, hold 10 sec. Also, full down, release, down 5 sec, full up, release, up 5 sec. Also some other combinations I've seen in the forums. Sometimes it appears to fix the problem for a couple days, then it acts up again. Any suggestions? Thanks!