For a brief time, version 1.1 was available for Firefox.  With Firefox’s new rapid release cycle, it became out of date shortly after it was approved.  Ah well.

A new version has been submitted.  It improves the handling of timers, has some bug fixes, and includes the latest version of Narcissus.  Most importantly, it supports up to FF version 8.0. It is pending approval, but you may find it here.