I can open multiple instances of some programs, but not of others. I use the little Stopwatch program, and in Gnome I could open as many stopwatches as I wanted. But Unity only allows me to have one of them open at a time.

For a year or so I've gotten around this by installing another timer called Zeegaree Lite, so then I can have two different timers open at once. But Zeegaree has become unreliable lately (it often stops itself before reaching zero), so I want to start having more than one Stopwatch again.

How do I change this setting?