Anyone experienced this? Set my shutter speed to 180 degrees and then when I go into Slow & Quick and set it to 60p for slow-motion, it automatically sets my shutter speed to 360 degrees. If I then change it back to 180, shoot the clip, then reset my framerate back to 24p, the shutter speed is now 72 degrees. It seems like it's doing this to maintain consistent exposure across frame rates, but it's annoying if I cannot turn it off.

Anyone else experiencing this and found a solution, or do I need to bug Canon about fixing this in a firmware update?

I have experienced this and also find it rather annoying, but I don't know of a good solution other than manually re-setting the shutter speed.

We are getting the same issue with the two cameras we bought.

Can you also ask for the option to be able to set the custom button to be able to change from AVCHD to MP4 with the push of a single button? :)

Yes, I'm seeing that too. Is the camera keeping the same actual shutter speed you just used, not the shutter angle? So, if you had 180 degrees on 24p, that's 1/48. What degree would 1/48 read if you were on 60p?