I have noticed a bug in 13.04. When I minimize something, I press the minimize button, but it doesn't want to minimize. Instead it will start to hang and won't go anywhere until I press Ctrl+Alt+Del.
I tested this across three different laptops and the behavior was replicated each time.
Is there anything I can do?
It's most likely a driver issue/gpu issue. Or corrupted install.
May I ask what the system specs are for one of the laptops? Usually you need to manually install GPU drivers, and preferably the proprietary ones (as in the ones AMD or nVidia support, as open source drivers are ok, but not the best).
In my case, before I updated to proprietary drivers on my desktop (I'm running on an old old GPU, a Quardro FX 560), I couldn't open the dashboard without it crashing the entire OS.
Or you could try something like metacity or something other than Unity, as Unity tends to have issues on older machines.
