Installation problem: No hard drives found

[Salvador Santander Gutierrez]

We've installed evaluation version obtained from Red Hat Network on a HP
Compaq dc7600 Ultraslim and all went well.
After we weceived the distributor CD's, we've thought it's better install
this CD's, but when we began the installation on the same computer, show a
error "No hard drives found" and the installtion stop.
This computer has a serial ata controller: Intel 82801GB/GR/GH (1CH7
Family).
It's strange that the same version and Update (3) in the distributor CD's
goes bad and the online CD's goes well.
Can we use the CD's obtained from the Red Hat Network instead of the
distirbutor CD's?
What happens?

Thanks.