You are much better off disabling the fake raid in bios and just using software raid:
http://wiki.centos.org/HowTos/SoftwareRAIDonCentOS5
http://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-raid-config.html
Or Google: centos 5 software raid.
Thanks Matt.
I have done sw raid on Centos before and have never had issues with it. . I think I will try it in this case, good idea.
- aurf