ethernet detection

[Larry Brigman <larry brigman gmail com>]

I am doing kickstart with RHEL5(.3) and IBM x3650 servers.  We have
Intel IGB GigE cards installed in these machines and sometimes
when we do the pxeboot install, it picks the IGB device as eth0 which is
on the PCI-E bus and misses the Broadcom BNX2 device on the motherboard.

Is there a way to detect or control this process.  We specify eth0 as
our ksdevice.
BTW this is using the newer Red hat kernel, 2.6.18-128.