you have to select the muss storage driver for your sata hardware.
Check your driver disk for linux driver and copy it to an fdd after that you can add that driver to recognise it by the system.
Same thing happens when you have an external usb DVD as well as an internal. And you boot from the external dvd and the installer start to search the disk image at the internal hardware.
I had to remove the internal CD-ROM in my proliant server. The CentOS installer started to loading the disk image from the CD-ROM even if I booted from the external USB DVD.
Anyway try to select Sata mass storgae drivers from the list or use just one physical media to install the system.
It might help.