[CentOS] Unsupported Hardware that works fine?

I recently purchased a set of ASRock Intel i5 MB/CPU combos for a budget compute cluster. Every time we load up a system and try to boot with a recent EL6/64 ISO, we get a message that reads:

This hardware (or a combination thereof) is not supported by CentOS.

For more

information on supported hardware, plesae refer to

http://www.centos.org/hardware

Not only does the hardware *seem* to work to expectations, but the url referenced goes to 404!

Having loaded CentOS6 on many systems without ever seeing this message, I have to ask how to determine what might be triggering it and whether or not I should be concerned?

Thanks