panic: bad pte

Hi,

I know this has been mentioned before on the list, and probably I should
know what to make of it, but still...

I'm getting this panic from time to time (not easy to reproduce, no
apparent pattern):

TPTE at 0xbfca06ec  IS ZERO _at_ VA 281bb000
panic: bad pte
at line 2558 in file /usr/src/sys/i386/i386/pmap.c


I was silly and just typed c so nothing more to work on I'm afraid.
Basically, what I'm asking is: what's it about? Is it hardware-related,
is it a know problem, or should I wait for it to happen again and look
into getting more details?

Bye,
	Andrea

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