After installing RH6.0 on a machine that had been happily
running 5.1 for several months, I have run into a problem.
Another user (rdnelson@princeton.edu) reports a similar
problem.  Running with an off-the-shelf 6.0 kernel
(2.2.5-15.i586) on an AMD K6-2/333 with 32M memory, the
machine locked up with the following message in
/var/log/messages:

Oct  7 17:36:50 mercury kernel: Unable to handle kernel NULL
pointer dereference at virtual address 00000004

For both of us, this problem seemed to occur while using
Netscape Communicator.  I have since upgraded to 2.2.5-22
and have not seen the problem again, but I don't know what
web site/page I was looking at that caused the problem
initially, or even if it was data-dependent.

I have been unable to determine what changes occurred
between release 15 and release 22, though the upgrade center
indicates 22 fixes a potential for "remotely hanging the
machine".

Could someone verify whether this is a known or fixed
problem?