I tried to drag and drop transmission to my launcher in Ubuntu 12.04, and this is what I got:
As you can see - there is an icon shaped space where an icon ought to be. Transmission is locked to the launcher - but I only know this from right-clicking on the space (which gives me the option to unlock it, as well as start the application minimised or with all downloads paused). Left-clicking on the space does not launch transmission. Why don't I have a launchable icon of Transmission in my launcher?