Ok, here is what I did..

i cut the ground wire from the rio to within several inces of the harness...and connected it to nothing!!

The whine went away...so all i have grounded now is the sled and the sony to the stock wiring harness ground point

i orignally had the ground from the rio running along the door into the trunk and grounded to where the amps are grounded..

now the rio is not grounded and all is fine!

go figure!