I have a asus f5r with a camera that can be rotated.
I am using archlinux and gnome.
Tested with "cheese" and "skype".
When seeing "in front of" computer the picture is upside down. If i rotate to see "myself" again while the cam is in use it hangs.
Both zones work as it should, but when rotating from one to another while it is capturing it hangs.
It is possible that while rotating the webcam there is an electrical contact issue. In this case, you should see in the dmesg that the webcam was disconnected. I have a F5RL (with a different webcam and thus driver) and I have this trouble, not always but it happens.