Sunroof Problem

The sunroof on my 99 A6 with 102K works intermitently. I replaced the switch last year because it seemed loose and kind of sloppy, but the problem has not gone away. When it works, you can open and close it in all positions repeatedly, so it does not appear to be the motor. When it does not work, it will not do anything at all, sometimes for days. Using the key in the door to raise and lower all 4 windows at the same time seems to help get it back in sync, but I am reluctant to open it in anything other than the vent position for fear that I will not be able to close it.

Is it a computer issue? A relay problem? Or does the motor go out intermitently?

Help!