Fri Nov 18 11:30:22 EST 2005 rsc
    Sorry, I'd much rather fix the panics than break paddr.
    There is plenty of sketchy code, but returning 0 in this
    one case would allow things like PADDR(PADDR(KADDR(0))),
    which I'm trying to catch.
    
    If code assumes it can pass low addresses to PADDR, that
    code needs to be fixed.  Where is it?
    
    Thanks.
    Russ