i would suggest :
Remove the cable connecting the hard drive to the main board
BE SURE TO USE THE CLIPS on both ends.
Some people dont know there are clips because it is possible to force the cable in and out with out realizing
there were any clips in there are all .
if you need to see how its done you can find videos on youtube.
Then put the cable back as perfectly as possible and lock the clip,
first do the hard drive end then do the main board and lock it into place.
i had a similar problem it got fixed after I reinserted the cable correctly.
then go to itunes and do a restore, then install rockbox.
hope it helps
alex