Currently Being ModeratedAug 23, 2012 6:21 AM (in response to wanda L)
What happens if you try a hard reset of the iPod with it still connected to your Mac? To do this, press and hold both the Select (Center) and Menu buttons together long enough for the Apple logo to appear.
If no luck, try manually placing the IPod into Disk Mode and connecting it to your Mac. From there you may want to restore it in iTunes.