I gave up. I've switched back to RH7 :-[. I've spent several late nights and most the weekend trying to figure out the difference between RH7.2 and 7. I did all can between using pump and dhcpcd. Nothing work. I concluded the difference is in the ifcfg scripts or the kernel-2.4. The MAC spoofing works very well on the RH7 - as exactly the way I said. Try it. No modem rebooting requires.

Ken