Possible memory problems with up to date 3.0 box

["Bryan K. Walton" <thisisnotmyid@tds.net>]

Hi,
	I have a dns server running current (with all security updates)
Debian 3.0.  The box has been very stable, running without any real
problems.  However things started to bad about 1 1/2 weeks ago.
	I noticed that I couldn't SSH into the box last week, was
getting a connection closed by remote host message.  A trip to the console
produced the following error on login attempts:

-- SNIP --
/bin/login: relocation error: /lib/libpam.so.0: undefined symbol:
	_pam_set_default_control7\eam_parse_control

-- END SNIP --

I rebooted the box, and the box came up cleanly.  Logins were working
again.

Now, a week later, and I have a very similar problem.  The same symptoms,
however, completely different error messages when trying to login:

-- SNIP --

Security: signal 11 (read or execute addr 0x7144f11c) sent (privileged)
to sshd [9260], UID 0, EUID 0, parent sshd [399], UID 0, EUID 0, by sshd
[9260], UID 0, EUID 0, parent sshd[399], UID 0, EUID 0

-- END SNIP --

Does anybody have any ideas what may be going on here?  Is this bad
memory possibly?

Thanks,
Bryan Walton