Actually friday20 might be right on this one. The remote code is very different across platforms. The way it works on non-Windows/non-Mac is very different, and

Actually friday20 might be right on this one. The remote code is very different across platforms. The way it works on non-Windows/non-Mac is very different, and it's possible that --new-instance doesn't work as expected there. On Linux/BSD/etc (everything that uses X11), --new-instance should be prefered.