formatting hard drive nightmare

ok... i've tried to format a toshiba mk1032gax 5400 rpm 16 mb cache 100gb hard drive as well as another toshiba (same model but 120 gb) drive on my mpc 1000. every time i try to format i get a "Format is Invalid" error and it doesn't work. i've tried formating on every OS including both of the JJ OSs and nothing has worked. i have not seen one posting of an issue similar to mine and have not really had any advice on what to do besides trial and error. i'm taking my mpc into the shop cause i assume it's the problem. any ideas before i throw it out the window?... been troubleshooting this for almost 6 months.
cheers.

are you sure the hd mounting kit is set inside firmly??? i had this problem and had to take it out twice and make sure it is sitting good.