My -current machine (1.6R as of 28 April or thereabouts) died with a 
"panic: setrunnable".  (Dump available on request...)  But the file 
system had a problem that upset fsck:  a directory had a link count of 
1, when it should have been 2.  I haven't seen that sort of thing in a 
long time.  (When I ran fsck manually and gave it permission to adjust 
that directory, it was happy, and only objected to one other i-node.)

		--Steve Bellovin, http://www.research.att.com/~smb (me)
		http://www.wilyhacker.com (2nd edition of "Firewalls" book)