Looks like Google have been caught napping slightly. Firefox 3.6 has been in development for while and has been out for nearly a week now and we still don't have an officially compatible version of the Google Page Speed extension.
Well, all is not lost, it appears Page Speed continues to work correctly and as expected in Firefox 3.6. All you need to do is bump the "
em:maxVersion" number in the
install.rdf file included in the extension. I've set this to
3.6.* and the extension works a treat.
If you already have the plugin installed, you'll just need to modify this file in the extension directory in the profile directory on your system. If you don't have the extension installed already, you'll need to unpack the extension (it's a zip file), make the change, repackage the extension (zip up the files with a .xpi extension) and try installing again.