[CentOS] Centos 4.1, ClamScan and Kernel Leaks

I recently installed ClamAV on my Centos 4.1 system (AMD Athlon 64 3500
+, 1GB RAM).  

I'm using postfix, with fetchmail to retrieve email from remote ISP
accounts and processing emai through a spamfilter plugin, which is a
shell script that passes inbounds through clamscan and spamassassin
before handing it off to a local procmail for processing and delivery.

Pror to installing ClamAV, the system stayed up for months at a time.
Since then, I'm seeing a lot of system freezes and crashes, at least
once per day.  I'm also seeing a fair number of complaints in the boot
log about ACPI errors and the like. 

I'm on kernel 2.6.9-11.EL.  In the messages log, I can see where just
prior to the system freeze, there are a sequence of messages regarding
the system's inability to reset the USB adapter, of which no devices are
attached.   Almost immediately after, I see errors with the system gets
error messages on read capacity on the hard drives.   After this appears
to reset itself, I start seeing kernel messages about available memory
dropping from 1GB to less than 1MB.

Any suggestions/advice?
Thanks,
Bill
-- 
Bill Diamond <bill at billdiamond.com>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.centos.org/pipermail/centos/attachments/20050724/05dede4b/attachment.sig>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3098 bytes
Desc: not available
URL: <http://lists.centos.org/pipermail/centos/attachments/20050724/05dede4b/attachment.bin>