Sometimes when I mouse click + drag to pan (left mouse) or change direction (right mouse) nothing happens. My cursor simply moves across the screen.
The problem seems to be quite random, sometimes it works, sometimes it doesn't.
I have diagnosed the problem to be Jamba 0.5g (I haven't tried previous versions) by uninstalling all addons. With no addons installed the problem is gone. Install Jamba only, and the problem is back.