spurious actions by copilot

As of late my copilot will do crazy things while completing a task. An example is while doing the flight control checks, they will start moving flaps, changing radios, changing the sim rate, etc. Another one is while on descent and final approach to Helsinki last evening she changed the sim rate 3 times. I am using the PMDG 747-400 in fs2004 and the latest update to MCE.

I have used MCE for over a year and love it except when the copilot goes bonkers and starts doing uncommanded tasks. I have started to mute my headset mic and that seems to help with some things, but the above has me puzzled as to why it would even happen.

Thanks, Paul