My Book AV not working

I just bought a My Book AV DVR extender.  My SA-8300HD Cablevision DVR has 4% of its memory filled (it will get higher when football season starts).  Whenever I hook up the hard drive, the memory used remains at 4%.  The instructions say if the drive is recognized properly then the percentage of memory used should decrease, but I can’t get that to happen.  Any ideas?


Did you tried connecting the my book to your computer, just to verify is working fine?