Exetremely slow sound during pushback + killing mechanic

EDIT: sorry about the duplicate post, everything seemed to freeze up and I posted again, please delete one

When I use pushback, I usually (always?) get an EXTREMELY slow wav playing as pushback commences. It's like an old 45 being turned at about 1 rpm ! It's too slow to decipher what is being said, but it has certainly happened when I run over the mechanic, I'm not sure but this may be the only time it happens. FSX & al addons are otherwise running smoothly.

This brings me to the second issue, possibly connected - I seem to keep running the mechanic down.
I know this has been posted and discussed, but I cannot seem to stop it happening.

I have removed GSX to see if it cures it, and set mce.ini back to native, but I am still getting the slow playback sound.

I have MCE, FSCaptain, and GSX(currently removed). Could someone please clarify, do all three of these have the pushback option, and how can I ensure just one process is taking place? Can I choose which version I use?
Is the slow playing file connected to this issue?

I am getting good response from the ground crew - I say 'mechanic you can leave now', and he responds something like 'pleasure working with you, we are disconnecting'. Should I then wait longer? Is there a further signal (other than Travis saying 'I think we killed the mechanic').

I'd appreciate any help in resolving these 'minor' issues. The sound thing is a mystery to me, and it just takes the edge off the flight when I taxi to the active with blood on the wheels.