Another panic in 1.6.x

[Petr Janda]

I think I have another PF panic, unfortunately I cant get a backtrace, 
even so there were backtraces from other people. The screen *seems* to 
be scrolling like this
db>
db>
db>
db>
....

at a very fast rate. I plugged in keyboard but it isnt responding. Why 
is this bug still not fixed? Ive just had 20 days uptime and this is 2nd 
time it happened in 2 months. If there is a such thing as a *gravely* 
bug, this is one.

Petr