[exim] Exim Segfault Error

I don't know if this is an Exim problem, hardware, or a kernel problem.
But Exim is what's crashing, has locked up the server twice, and it's
always at the same location. Riunning Exim 4.63. I tried cocompiling and
reinstalled. Running on Fedora Core 5 with the latest upgrades, except
for a custom kernel to fix a motherboard related problem.

Just put a new server online trying out the new AMD AM2 processor. I
compiled a custom kernel because the regular Fedora Core kernels aren't
yet compatible with my Asus M2NPV-VM motherboard using the nVidia chipset.

I compiled 2.6.18rc6 and got segfault errors. So I tried the 2.6.17.13
kernel and same thing. About every 20 minutes or so I get one of these.

Sep 11 12:05:18 pascal kernel: exim[19840]: segfault at 0000000000000000
rip 0000003f53e73ee0 rsp 00007fff9e561d18 error 4

At one point the server locked up. Before I put it online I did several
days of memory testing with no errors. I believe the Exim code is solid
as it has been running flawlessly on all my other servers.

It's probably hardware or some incompatibility but I'm not sure where to
start looking. Trying to understand what this error means. What is Error
4? How do I track this down?

Thanks in advance.