http://userscripts.org/scripts/show/7710
(is an older version.)
and have had all sorts of mysterious problems that seem to come and go.
E.g: Greasemonkey never running on top-levels pages or iframes, cross-site
errors when things are really at the same site (i.e: the script tries to find
an ID in a sub-frame and throws "uncaught exception: Permission denied to get
property HTMLDocument.getElementById"), the "busy" mouse cursor icon not going
away either on the page or in the chrome, and other weird stuff that hasn't
recurred for me to get a handle on it
Given that there has been discussion on the Firebug list
http://groups.google.com/group/firebug/topics
along the lines that "firebug breaks Ajax".
I guessed maybe that Firebug was causing my script problems. For the last 26
hours I have had Firebug disabled and haven't had any mysterious problems.
Firebug 1.01, Greasemonkey 0.6.8.20070307.0, Firefox 2.0.0.2