It might help to change the SATA mode in the motherboard's BIOS to "compatible" or something along those lines... (I sincerely doubt you will notice much, if any, performance loss.
Failing that...
I think I ran into this a while back. Digging through some notes I think that update3 was one of the first to include a kernel that worked with most of the common SATA controller vendors...
Here's a link:
https://rhn.redhat.com/errata/RHSA-2006-0132.html
Probably the easiest thing to do would be to download the most up-to-date RHEL4 installation ISO's and perform your install using them instead. For that you will need a valid support contract...
If you want the stability of RHEL without the official support (and accompanying price) I recommend considering CentOS. It's the community-supported release of RHEL, 99% identical in every way, built from the same Redhat-supplied source.
Check out CentOS at
http://www.centos.org