Dell C640 Diagnostic Boot Selected frustration

[mksmith713]

I have a Dell Latitude C640.I keep getting a "Diagnostic Boot Selected" message on start up.
I have to keep hitting the escape key to by pass this extremely long and annoying POST.
After hitting the esc key repeatedly, it boots just fine.
I went into the BIOS to make any changes I thought might stop this but nothing seems to work.
I formatted the HDD,swapped out the HDD, replaced the CMOS battery, even went so far as to swap out the mainboard and I still get that same message on start up.
Has anyone else experienced this?
If so, did you find a fix for it?
I have a sneaking suspicion that the message might be originating in th Eeprom.
Any ideas or help will be greatly appreciated.