VS2010 CTRL+M keyboard shortcut has stopped working

Question

I have a strange problem which seems to have recently appeared. I used to be able to press the keyboard shortcut CTRL + M + O to \'collapse

Answer 1

Reboot worked for me.

I experienced this same issue out of nowhere (CTRL+M stopped responding).

I read the suggestions here but I could not find what process was causing it. I rebooted my laptop & the problem was solved!