Comment 4 for bug 773028

This seems to be a bug but please mention that if for instance you drag an image from i.e. firefox and the bar appear, and you drag the image inside the bar, then the system hangs for a second or two and then it makes invisible all the launcher icons except from GIMP and Firefox (2 known applications than can open images).

On the other hand, this isn't happening while dragging text (all the programs become invisible while dragging text above the bar, including gedit) and that's probably the actual bug!