Car Dock / Bluetooth issue

[truman_33]

I have a Samsung car dock that I purchased from the T-Mobile store. When I put Galaxy S 4G in my car dock, and I use the phone, the cradle seems to force phone to use speaker, not bluetooth. I have to manually deselect speakerphone and select headset each time. If phone isn't in the cradle I don't have this problem; but that defeats the purpose. When it's docked, the phone activates the bluetooth automatically, but when I try to make a call, it defaults to the speakerphone function rather than the headset. It makes no sense!! I called T-Mobile, but they were absolutely no help at all. I am probably going to call Samsung, unless anyone has any brilliant ideas that can fix this stupidity. Anyone??