I have tried that. Cleared the CMOS by using the jumpers with both drives disconnected, reconnected using only the Crucial drive and it brings up the same message saying 'the boot selection failed because a required device is inaccessible'.
Having plugged the Samsung back in, it recognises that with no problem but just won't recognise the Crucial no matter what.
Any other ideas or thoughts? Generally how do warranties on these drives work?