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
I'm running VS2010 inside VMWare Fusion on a Mac.
For me, it stopped working after updating VMWare Fusion to version 4.1.2
I fixed it by unticking "Minimize Window (⌘ - M)" in Preferences > Keyboard & Mouse > Fusion Shortcuts.