Thanks for your report, we will study it and fix that bug within couple of days. It is really hard to keep addon up to date, since Mozilla creates new version of Firefox faster than you can have your addon approved by their staff.
Currently we have finished our stand alone Premium Proxy Switcher Portable for all 5 browsers. In addition it includes local proxy checker with many useful features. Also we added proxy chain support for better security + for those users who are forced to use local proxy server (there are no standard way to use proxy for them). If you are interested please let us know and we will send you beta version of that program.
Waiting for your reply
p.s. Officially the program should be available at premiumproxyswitcher.com web site several weeks ago but the delay was caused by many beta testers who asked us to add proxy checking (at first it should come with second version), nice design and other nessesary options. If you are interested, here is the screenshots:
