np..

have had a prob with (even on old drives) when 40 cor cable used on new boards..

is it possable a pin isnt bent in the socket on the mobo,

are you able to try a newer HDD (not so easy for some sry)
for that matter is it possable to double check your drives in another machine?

hmmm also.. do a full reset on the MOBO.. then see what happens..last step b4 returning

I think I have covered all bases..