Rated 3 out of 5 stars

@Laurens truthly speaking, when I choose the menu option "Launch another profile" and then I click in the new desired profile and finally hit yes in the dialog that pops up if I wish to restart the browser with a new profile if I choose yes Firefox closes itself but never shows up again.

This review is for a previous version of the add-on (1.7.5.1-signed).  This user has a previous review of this add-on.

This bug should be fixed in 1.7.6 version, released now.
A workaround is to set the preference "extensions.profileswitcher.use_onbeforeunload" to false, but I suggest to try before the new version.