Canon 7D Firmware 2.0 Audio Issues

I upgraded both of my camera's to the new 2.0 firmware. However, when setting the audio to manual with a rode videomic pro plugged in, the levels never drop to zero and maintain a noise. I tried 2 rodemic pro's on both of my 7D's and the same issue occurred, once I unplug them, the levels drop to zero and work perfectly with just the onboard mic. I also tried a zoom h4n and though the result was a lower hum, the levels never dropped to zero in a quiet room... just maintained a low hum. Obviously I adjusted the audio manually but the only way for the room to register with no noise was to unplug the mic. I tested the same mic's on a 5d mark ii and the levels were perfect when adjusting manually and there was no constant hum/noise.

Anyone else test this?

I have the same issues with the firmware 2.0. Unfortunately I did not test signal/noise ratio before firmware update. Has somebody do it ?... In order to separate hardware or firmware influence.

You couldn't, since you couldn't set any manual recording levels at all prior to the firmware upgrade.

Yes of course. But if you plug the empty jack (with e.g. 100 OHM resistors to gnd ) to the mic input, you should not have an extremely high noise with the automatic gain control too. Fast Test result, FW2.0: Auto--internal mic, quiet room, level about -40dB for both L+R. Auto--plugged jack with 100 Ohm resistors, L about -25 dB noise, R about -35 dB noise. /note pls. not yet calibrated the dB scale/.
Seems to be something wrong in input amplifier.