Rated 5 out of 5 stars
can't be installed sadly not compatible
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:2.0b13pre) Gecko/20110321 Firefox/4.0b13pre
It is because you are using 64bit version of Firefox, which is not officially supported by Mozilla and that is why we do not provide 64bit version of the plugin. However, you can install 32bit FF on both 32bit and 64bit Windows.