I installed Adobe Master Collection CS5.5 on a new MacBook Air and when I open a document (new or previously created image) and I make the window for the document larger then the image itself, you can see that Photoshop is showing a strange gray rounded corner border around the image, and the 'blank space' (around the image where the window in larger then the image) is showing black when every other install of Photoshop I have (on other computers) (both CS5 and CS 5.5 installed from same discs) doesn't show the border and the 'blank space' is gray.
Googling I found some posts that sounded kind of similar saying you can change the background back to gray by Control-Clicking the 'blank space' and choosing Gray, however mine says that gray is selected and changing it (to black, custom, and back to gray) does nothing.
I have tried uninstalling and reinstalling. I have also tried resetting Photoshop's preferences, all with no effect.
Does anyone know what is going on, or more importantly just how to fix it?
(Screen shots attached)