I have found a strange, reproducible issue with Googlebar Lite in Firefox 4 builds. Immediately after customizing the browser toolbars, if you attempt to use the Googlebar Lite search box, both the autocomplete mechanisms and search mechanisms will fail. Looking into the error console isn't showing me any errors, though I'm using a production-level version of the extension (not my development copy). I will continue to look into this problem in the next few days, and will hopefully have a solution soon. Until then, you'll need to force a browser restart after customizing the toolbars in order to use the extension properly.