I made this thread earlier: Awesome wm slow when switching tabs
Now I have installed xfce4 instead, but the problem seems to have translated to this DE as well. When I switch work spaces by scrolling or clicking, if there is an open on that space, like Iceweasel or synaptic, then there will be a 1 - 2 second delay before it appears.
Note that before installing debian (before I made the other thread) I had Ubuntu 13.10 unity where there were no similar issues at all, and everything was quick and smooth.
What may be the cause of this problem and how do we fix it?