CentOS - Apr 2007 - network config files in centos 5 changing - more information

Log file shows: MAC address issue.

Apr 25 08:32:19 fsdsigns kernel: ACPI: PCI Interrupt 0000:00:07.0[A] -> 
Link [APCH] -> GSI 20 (level, low) -> IRQ 209
Apr 25 08:32:19 fsdsigns kernel: forcedeth: using HIGHDMA
Apr 25 08:32:19 fsdsigns kernel: 0000:00:07.0: Invalid Mac address 
detected: 19:ea:64:4d:1a:00
Apr 25 08:32:19 fsdsigns kernel: Please complain to your hardware 
vendor. Switching to a random MAC.
Apr 25 08:32:19 fsdsigns kernel: eth1: forcedeth.c: subsystem: 
01458:e000 bound to 0000:00:07.0

Now I had an Asus motherboard and was getting this error.
I said fine and got tired of messing with it and bought a Gigabyte 
motherboard.
Now I am having the same issue. Its complaining about a bad MAC address.

I actually have 2 identical boxes. One has this issue the other seems to 
be OK.
The network settings are not changing every time I boot up.

So - How can I tell centos to STOP changing my ifcfg-eth* config files?

Thanks so much,

Jerry