Ok. Passing on to acpi-devel@xxxxxxxxxxxxxxxxxxxxxx
I've looked in the archives, and the problem looks very much like the one in this thread:
http://sourceforge.net/mailarchive/forum.php?thread_id=4172848&forum_id=6102
And I've been noticing some keyboard glitches too, but these were to unfrequent, and usually occur only in one application (gaim) so I figured it might be a bug in gaim... guess not...
Unfortunately, the hints in this thread don't help. I've browsed the input system FAQ, but no dice.
The only thing that gives me a working synaptics touchpad is acpi=off.
It worked fine with 2.6.5.
Jan