I had similar problems which was solved by one of two things. (It happened with an original tuner module)

1. Was using a tuner extension cable
2. I tapped power from the tuner extension cable for my cellphone handsfree kit.

When I got rid of the extension cable and tapped power somewhere else for the handsfree kit the problems went away. Did both at the same time so I don't know which was the cause. Anyway you might want to check your tuner to empeg connections to make sure they are correct.