Comment 48 for bug 78538

Here's a simple example of how I use multiple screens, and how I expect Firefox to behave.

Most of the time, I have a Firefox window open on the centre monitor (usually :0.1). I have it configured to open new tabs by default instead of new windows.

I run my IRC client on the left monitor (:0.0) - this is usually where I end up clicking links to have them to open in Firefox. This actually works for me currently -- when I open a link, it opens in a new tab of the firefox window on :0.1. This behaviour is exactly how I want it -- I opened firefox on the centre monitor because I typically want to use firefox on the centre monitor. I never want to use it on the left monitor, that's for IRC.

Now, say I want to work on something. I put my work on the centre monitor, because it is largest. At the same time, I want to put up documentation or something on the right monitor (:0.2). At this point, I bring up my root menu and select "Firefox" on the right monitor, expecting a firefox window to open there. Currently, this will fail because it can't lock the profile, and I have to totally quit firefox on the centre monitor just so I can open a single page on the right monitor.