I'm using PyCharm with multiple monitors on Mac OSX (10.10.5), normally you can drag windows off to a separate monitor. In PyCharm that works, but they (and in particular the Run window) snap back to the main monitor.
I've only seen this on the latest PyCharm 5 CE though its possible older versions also had the problem. I've searched all the settings and searched online, but can't find a setting that makes the window stay where it was placed.