Ok, I think I found the cause of my "Rotation Mode". It seems to be caused by using cmd-Tab to switch between apps.
Please do the following:


Open TextEdit

Open MoI and draw a solid box

Press cmd-Tab and switch to TextEdit

Write something

Press cmd-Tab and switch back to MoI

Try to select a surface of the box.

Voila, instant "Rotation Mode"

 

It only "works" if you use cmd-Tab to switch between MoI and another app.
A way to get out of "Rotation Mode" is to change back to MoI by clicking into the MoI window instead of using cmd-Tab.
I hope you can simulate that behaviour.

Update: It seems to fail only when there is no clicking involved while switching between the two apps.