FC5.ppc half-losing mouse

[Beartooth]

"Half-losing" doesn't sound like sense, but neither is what it needs to
describe.

I have FC5.ppc running, after a failed upgrade and a clean install, on a
G3 iBook. When it sits for a while, it half-freezes -- there's still a
cursor, and the mouse moves it fine; but clicking no longer has any
effect. 

Neither does Ctrl-Alt-Delete, nor the power button. The only way I
can regain control is to disconnect the power cord and loosen the battery,
then replace it and boot with the power button. (I seem to recall that
that's supposed to be very bad; but nothing else rescues it from
doorstophood.)

This is with the same optical USB  "contour unimouse", plugged into the
same USB port, as it has always been, since I bought it in summer 2002
with OSX and YellowDog. And I've never seen such a symptom anywhere.

What's happening, and what do I do about it??

-- 
Beartooth Staffwright, PhD Neo-Redneck Linux Convert
FC5; CXO 5.0.1; Pine 4.64, Pan 0.14.2.91; Privoxy 3.0.3;
Dillo 0.8.5, Galeon 2.0.1, Epiphany 2.14, Opera 8.54, Firefox 1.5
Remember I know precious little of what I am talking about.