Hi paulhebner! I use Windows 8.1 and Firefox 25, so my suggestions may not work for you, but I have found that after a certain number of upgrades on Firefox instead of clean installs, I run into problems. Folders permissions are a funny thing and can get screwy over time and multiple upgrades. A short version of fixing this may just involve changing the permissions on the Firefox folder, but that can ***** up other things down the road sometimes. I would try the below..... I highly recommend that you completely uninstall Firefox using something like Revo Uninstaller or Ashampoo Uninstaller 5. There are a lot of uninstallers, but you need one that can search for all the Firefox files that would be left over after a regular uninstall (there are a lot) and delete them. You will first want to back up all your bookmarks and plugin data, and save all your preferred plugins by creating an account at Firefox's Add-Ons site and creating a list of your favorites. Your goal in the end is a fresh install of Firefox AND Adobe Flash AND Sun Java with zero older residual files or registry entries from the older program versions. Actually, you will want to uninstall Flash and Java first, also using Revo Uninstaller or something similar. Even after that, Adobe Flash and Java can stubbornly leave files on your system, so manually search for files and folders called Adobe, Macromedia, Sun and Java. The stubborn remaining files and folders typically reside in the Windows\System32 (and SysWow64 on 64 bit systems) folder after uninstalling the programs. They should all go unless you have programs like Adobe Reader or some other Macromedia related program installed (you can see what related programs may be installed by looking inside the Adobe or Macromedia folders to see if anything besides Flash or Java is labeled/shown in either one. If you already know all that, I apologize for the detailed description. Once Flash, Java, and Firefox are all gone, reboot for good measure. Then install brand new copies of all three as well as your Evernote plugin. Do not install any other plugins prior to Evernote. See if you still have difficulties. Also make sure your XP install has all its updates. Use restore points during all of this if you like in case any Windows updates mess something else up or you delete something important while cleaning out old Firefox, Flash and Java installations. One final suggestion....if the plugin still does not work well for you, perhaps the Evernote desktop version would be successful?