Inexplicably yesterday's (and the day before) Debian testing snapshot
seems to have the problem fixed!
I tested kernel 3.2.x and 3.1.x. udev still is at version 175.
I'm completely ignorant to what change in Debian testing led to the
fixing of this problem. I guess I should have tested everyday, for
every round of updates to testing, but I lacked the time.
I'm attaching a dmesg, though it shows nothing of interest AFAIK.
I hope this issue doesn't come back to haunt me. I'll upgrade to
wheezy on this machine soon so I can monitor everything more closely
instead of relying on live images.
Cheers,
Andres