Be careful with old versions!
These versions are displayed for reference and testing purposes. You should always use the latest version of an add-on.
More information about it:
Users are strongly advised to update to this version as soon as possible, as I'm moving the server (which does the caching and resovling or URLs) and hence the IP will change.
After the moving is done, user running the old version of this addon won't be able to resolve any URLs anymore. However, this won't break any functionallity with the browser, you will just see the normal unshorted URLs as without the addon.