7D Firmware 2.0 Audio Issue

After upgrading to firmware 2.0 and plugging in an external mic in manual mode, the levels never drop to zero. There is a huge aount of noise, especially on the right channel. I've tried several cables and mics and also my Sony PCM-D50 recorder. As expected, the recordings sound noisy … The internal mic works fine, levels dropping down to zero on the meter like they should.

Now, it's difficult to tell if the noise was there with FW 1.2.5, because I did not use an external mic at the time. Also 1.2.5 didnt have any audio meters to reveal the noise.

I also have a relatively new 7D at work – same thing there.

Anyone else having this problem? Or better, a solution?