aa9b295 created the issue

Somewhat all of a sudden, dragging a file into the browser window to upload has become very sluggish. Instead of immediately recognizing the file and the directory to which I've dragged it, it hangs and takes several seconds to recognize the directory I'm hovering and the dragged file in general. Then when I release the drag, it again hangs for several seconds on the green (+) mouse icon before finally initializing the transfer. But even then, while initializing the transfer, I get the spinning beach-ball of death for a few more seconds, then the transfer starts.

This used to be much much smoother and quicker. Maybe it's Mountain Lion's file-dragging 'enhancements' that's messing with it, except other programs with drag-and-drop functionality don't seem to hang like Cyberduck does.