Okay.  Here I am, on my IIcx running 1.2 -current from late September, with
an old Apple extended keyboard and one of those newer, rounded-off-looking
Apple mice attached to it (I've been running MacBSD for well over a year now
and have never had *any* problem related to ADB whatsoever).  Just a few
moments ago, I wished to select and copy some text in dt, so I hit Command-P
to bring up the cursor and go about my business.  However, what happened was
dt acted as though I were holding down the mouse button, when in fact
I had yet to even touch the thing.  Odd, I thought to myself, but I assumed
I had perhaps brushed it lightly with my finger or something, and attempted
to finish the selection with another click.  Nothing happens.  Text still
highlighted, following the cursor around as though the button were down.
This is not good.  I hit some keys.  Sure enough, the keyboard is completely
unresponsive.  Bad bad bad.  After an initial panic, I tried hitting Command-
P again to shut the mouse off, which returned control of my keyboard to me (
I was, however, unable to switch VT's with Command-2, etc).  I tried going
back into mouse mode again, and the same thing happened.  So from that one
VT I was left with, I killed off dt and tried every bit of voodoo I could
think of, from catting garbage to /dev/adb to *remaking* /dev/adb to
attempting to write a little program to make use of the ioctl call to
reset the ADB bus (I think I probably botched it, but either way it did
nothing) to unplugging the damn mouse and replugging it like 30 times.  Same
stuff.  Then I began to think it was perhaps a dt bug, and fired up X to
test my theory.  But alas, X produces a similar condition; the mouse will
not respond to any clicks, but the cursor does not focus windows when
dragged over them.  The behavior in X also produced a number of other
bizarre effects which I don't quite remember.  Either way, something's got
screwed, and I can't tell if it's hardware or software.

I have a current uptime of about 20 days and I really don't feel like rebooting;
I should note that I did run into this identical situation a couple of months ago
and was forced to reboot to fix it, but at the time I didn't really think much
of the whole thing.

So, as my box sits here in mouse-challenged limbo, I ask:  anyone even *seen*
this happen before?  :)  I'd be pretty happy even just to know what's causing
this, because I'm completely stumped.  Thanks for your time, guys.