There is a strange and annoying thing in 12.04LTS: Sometimes (quite often indeed) when I click a launcher icon of an application that is running in a unity desktop different from the one I'm actually working in this app's window is repositioned somewhere between the desktops, e.g. the upper half of the window appears in the upper left desktop, and the lower half in the lower left desktop. Unfortunately I don't have enough reputation to post a screenshot, I hope you can imagine.
I've got the feeling that whether the problem occurs or not has got somethng to do with the total number of open windows but I'm not sure about that.
Is there anything to prevent that? Thanks in advance