As I recall my solution was to comment out the modprobe alias created for the network cards (/etc/modprobe.conf) and then in network-scripts, use the HWADDR in each config script. Make sure the device=ethX matches the name of the file, if nothing else, for your own sanity - since the OS checks that line, and does not care what the file is named.
Thank you for your answer. I will look it up.
I found this useful article:
Linux Enumeration of NICs http://linux.dell.com/files/whitepapers/nic-enum-whitepaper-v4.pdf
The author, a Dell employee, made a script to automate the process of ordering the NICs. He also gives tips to manually solve this recurring problem.
Regards Miguel