I have a problem with your C2SBX motherboard with BIOS: R1.2a, when SATA hard drives are connected to SATA0 and SATA1 port of the motherboard and setup the
Host RAID (RAID1) composition with Intel codebase.
Under such a condition, SATA DVD-ROM is connected with SATA2 or SATA3 port of motherboard, but it can't be detected in BIOS and RAID option rom will be disappeared, the problem only happens when Intel RAID is enabled. What could be the issue?
The issue might be insufficient Shadow Ram, please enable the "Extend Shadow Ram" in the motherboard BIOS under Advanced-->Boot Features.