there is no reason not to as far as i know. the closest warning i can recall to this one is that you shouldn't put a cd-rom on the same IDE cable as a HDD, that is true because of it's parallel nature that decreases bandwidth available to the HDD. however, seeing as the IDE drives and SATA drives are attached to completely different interfaces there is no conceivable hardware issue. there could be a software issue i don't know of. my guess is your instructor is an old school techie who has having trouble adapting to the new standards introduced.