Looking into it, I see that the goalCmp function (which compares two goals to determine their sort order), isn’t actually symmetric or reflexive, the way a comparison function is supposed to be. Firefox happens to do the correct thing regardless, which is probably why I never noticed the bug. In any case, I’ve fixed it, and published a new release which includes both this fix and also few small additional updates I never got around to publishing. (The search box now works a bit more like Altbee’s does: you can search for multiple space-separated terms at once, separated by spaces.)
Here is a download link for the Firefox extension, and here is a zip file you can use with Chrome. [EDIT: This is no longer the latest version. See here for the updated download links.]