I've never seen it while running about two months of Release 3.
I have only one display and keyboard for CPU and file server
and another machine.  In most times keyboard is off from the
CPU server...

By the way, thanks for your patch to Alef, now I'm running news
file server written in Alef (by Charles) on Release 3 Plan 9 system.

Yesterday, my release 2 CPU server retired from our office with best 
respects from me.  That file server was turned off the power, and still 
is waiting when I'll meet neccessity of updated release 2 sources.

Kenji