Failed to update Unity Web Player in Firefox

I’m a little confused, I can download the Unity 3D web player in Google Chrome, Internet Explorer and Opera, BUT if I try to download it in Firefox 13.0.1, I get the following error from “error details”:-
“Failed to update Unity Web Player” / “Unity Web Player (Mono) update finished, but installed revision (3518002) is less than required revision (3528002). Please reinstall.” error message. If I click “install manually”, I get a download, but it still shows that same error when I try and run the games

The downloads tried are from the same PC, the same Facebook game pages and the same download links. (They are all https)

I have unistalled from Control Panel>add/remove programs and tried each in turn after this and it’s only Firefox that gives this error. I have secure browsing disabled, pop ups enabled and java script enabled with Firefox and there is nothing in exceptions

Would really appreciate any help/advice, even if it’s a really obvious answer that I have missed in the settings

cheers

just an FYI-
someone has given me an answer that works, and that is to clear the Firefox cache as it was storing the old version, I did this and now the download works, I’ve put this here in case anyone else experiences the same problem