Be careful with old versions!
These versions are displayed for reference and testing purposes. You should always use the latest version of an add-on.
Firefox 4 beta users: due to issues with catching uninstall event in Firefox 4 Beta, uninstalling the addon might change your default address bar search (this happen if you uninstall the addon while InstantFirefox search page is open). To manually reset your firefox regular google search please change the keyword.URL preference back to http://www.google.com/search?ie=UTF-8&oe=UTF-8&sourceid=navclient&gfns=1&q= (or send email to feedback [at] instantfirefox.com and I will send you step-by-step instructions for that).
All functionality of the addon remain and work the same and this issue affect Firefox 4 beta users only.