Right click while dragging breaks mouse cursor

[Erik S]

I'm using Xubuntu 12.10 with gthumb 3.1.2

~$ gthumb --version
gthumb 3.1.2, Copyright © 2001-2010 Free Software Foundation, Inc.

When I move (with click and holding the left mouse key) within a picture and accidentally click the right mouse button, the mouse cursor keeps that "grabbing hand"-icon and nothing is clickable anymore.
The whole screen looks frozen. No mouse-hover effects, no reaction to clicks, and nearly no possibility to return.

An easy workaround on XFCE 4.10 (maybe also on other desktops): Switch to another workspace with keyboard-shortcuts. The mouse will be fine again.