xp系统，火狐11正式版，安装了这个扩展，单击火狐的退出，会导致进程无法自行结束，内存飙升，cpu 100%；存在内存溢出漏洞，请尽快验证修复。 （on windows xp, firefox 11. Use this addon, then click firefox exit menu, you will see 'firefox.exe' process cannot proper stop over itself, the memory will soaring, and CPU 100%; There are some memory overrun vulnerabilities, please verify repair as soon as possible. ）
For English you need to create the mentioned preference as a "string" pref. Also, the toolbar button is automatically placed on the Add-on Bar (ain't gonna see it if the Add-on Bar is hidden), not placed in the Palette as I would have expected. "About this Add-on" comments on the /en-US/ addons website should be in English.