OS X Mountain Lion Cannot Drag Items Into Finder

With Lion, I could drag a document from the desktop and hover over the finder icon on the dock. This would open finder, allowing me to place the document in a desired location. With Mountain Lion, however, When i hover over the finder icon, the screen fades to black, but finder does not open. This "fade out" is similar to the "App Exposé" function, except no dock appears (swiping down with 3 fingers for most macbooks). Any ideas?