iPhone now not recognized by RCA RC65i Made for iPhone clock radio dock 3G

After the latest firmware and iPhone 3.1 updates, my 3g iPhone no longer works with my RCA RC65i. Worked just fine from day one right up until the update. As my wife has the EXACT same RCA RC65i, I tested on another unit that has never had an iPhone attached...Same issue. When I connect the phone to the dock, the this accessory was not made for iPhone. Do you want to turn on airplane mode? diaglog pops up. Either answer is wrong as the line in on the dock connector is no longer transmitting to the dock. All sounds come through the iPhone speakers. Any ideas...have already done full restore on phone, and next thought is a visit to the Genius Bar.
MacBook Mac OS X (10.6.1)