I have noticed two small graphic bugs in Mint 14 Cinnamon. The first one is that sometimes the top left corner of a window (of the window manager decoration) becomes black or disappear. The affected window keeps this hole until I close the window.
I don't know if the second one is a bug, but it looks strange. If I right-click on the desktop background, a context menu appears, which has some letters underlined. But if I move the mouse cursor in the menu, all underlined letters become non-underlined.