I think this is an expected behaviour under unity. When an instance of an application is already running, if you need to open another instance under unity, you have to MIDDLE click the launcher icon and not left click. This feature was introduced as a fix for bug 709707.
There used to be a new window button. This was dropped to incorporate the middle click option. See Mark Shuttleworth's comment https://bugs.launchpad.net/unity/+bug/709707/comments/3 In my opinion this bug should be closed. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/760437 Title: Can't start firefox when a download is in progress -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs