Thanks for the question and welcome to the community. The Firefox addon sometimes encounters a hitch when updating, especially in Firefox 4. The easiest way to resolve this is to simply uninstall the current addon, restart Firefox, install the new one, and restart FF again. This should get up updated to the latest version of the add-on (version 184.108.40.2062).
I hope this helps, but if you have any problems with this procedure, or have any other issues, please feel free to contact our support directly.
Is there a way of forcing a download of the latest addon? I've just upgraded to Firefox 4 again (having previously reverted to 3.6). I've removed the Logmein addon, restarted firefox and logged back into Logmein, and my connection is just repeatedly fails. Checking the FF Addons, there's no mention of Logmein being installed.
Clearly the auto-install feature isn't working for me.