Under some conditions the eepro100 driver (v1.09j-t, rev 1.36) included with RedHat (Roswell) may complain that the EEPROM checksum is invalid and then set the MAC address to all F's. The checksum is supposed to be BABA. It appears to misbehave under the 2.4.7 and 2.4.6 kernels.
During an investigation of the eepro100 driver in the last few days several issues were found (and fixed) that could explain such behavior. These fixes will be in a kernel with version tag 2.4.7-2.1 or later, and such a kernel can be made available on short notice to Compaq for testing if desired.
This defect is considered MUST-FIX for Fairfax.
Have you used the e100 driver before ? It writes to the eeprom and might have left it in an invalid state
Per info on the ia64 mailing list this was caused by some kernel bug. Have not experienced this failure since the 2.4.7 kernel.