Hi PaQ, that's kind of cool - sort of a "ghost frame"... :)

Most definitely a bug though, thanks for reporting it, it's now on my list of ones to track down over the next few days here.

Looks like mostly a visual feedback glitch since the frame gets corrected when you finish doing the drag, should be easy to track down. There is something that tries to optimize the display of the frame while dragging to avoid bounding box calculations on every mouse move, looks like that is off.

- Michael