When I opened photoshop cs6 just now, the fancy new splash screen popped up and went away as normal, only the drop shadow around the outline of the splash screen has stayed on my desktop... At first it was over top of any windows I had open, but as I clicked on windows it fell behind them and was finally placed over top of my desktop wallpaper.
Heres a couple of screenshots to better illustrate what I'm left with, on two different wallpapers.
I'm using kuvva to update the desktop picture and I'm running Mountain Lion on a 2010 MBP.
Has anyone experienced a similar issue or know whats caused it?
UPDATE: I've noticed if I Expose Photoshop, the drop shadow is a selectable window. See additional picture below: