Andy M:

You described an issue with whine from the REAR, whereas the title of this thread suggests to me that the original poster thought the problem was only with the fronts..

Weird.

Anybody with a Home Dock (from me) can very easily check the FRONT grounds with an ohm meter -- just dock your player, and check resistance between the player's case (use the side vent holes for access) and the rear mounted RCA plugs. Mine measure about 0.0 Ohms: definitely grounded.

Cheers