128gb ocz octane (sata II type) - boot disk
750gb seagate barracude (connected via marvel raid card on pcie)
lg dvd-rw optic drive(sata II)
To be honest I haven't done much fiddling and swapping components, but does this sounds like a Mobo problem, PSU etc? Initially I was blaming the SSD (as it's an old type and potentially prone to failure) but seeing the cd drive drop out as well leads my to believe the mobo is playing up.