I noticed this strange issue with unity. I am using 12.04. The desktop has 4 virtual desktops, which I can switch between using the 'workspace switcher' which is very nice.
But I noticed the following: When I have 2 instances of the same app (say 2 different firefox windows, or 2 different terminal windows), in 2 different virtual desktops, then I click on the icon for that application located on the launcher panel (the left long strip with icons on it), then I see the application comes into focus. Then when I click again right away (on the same icon on the launcher), then now all instances of this application that are open come into ONE view (may be on was on desktop 1, and the other was on desktop 3 for example) and then I can now click on the one instance window that I want to select to use.
This is all very nice actually.
But this does NOT work for all applications!
I just tried it, and it worked for firefox, and for gedit and for the gnome terminal.
I have one firefox window open in virtual desktop 1, and another window open in virtual desktop 2. I clicked once on the firefox icon, then again, and both windows came into the main desktop and I was able to select which one to use.
When I tried the same thing on dolphin file manager, which I also had 2 windows (instances) of it open in 2 different virtual desktops, this behavior did not happen. I clicked again, and nothing happened. Only one remained in focus. So I had to fo look for the second dolphin window the hard way.
It looks like some apps are supported by this feature and some are not.
How does one make it so that all applications are supported like this? This is a very handy feature. Is it a configuration item somewhere?