Cannot open root device "<NULL>"

Hi all !,

I am trying to install FC4 on this box:

-- Intel Server Board SE7320vp2 (Complete box is under number SR1435vp2)
-- Dual Xeon
-- 4Gb RAM
-- 2 SATA (trying to get them working on raid, using raid from board)
-- booting from DVD

Message before Kernel Panic is:

RAMDISK: Couldn't find valid RAM disk image starting at 0.
VFS: Cannot open root device "<NULL>" or unknown-block(3,2)
Please append a coorect "root=" boot opntion

I try it, but it works once ...

Have any one some ad, please ?.

Thank you very much,
Jorge.