Rep he is talking about the movreel BS box for the download manger thingy.
He is doing it correct.
To the OP have you cleared your Browser Cache / Download History ?
This is copied from mozillazine Unable to save or download fileshttp://kb.mozillazine.org/Unable_to_sav ... load_files
Clear the download history
In the Firefox (Tools) menu, go "Downloads" and click "Clear List". This will remove the stored history of downloaded files in Firefox, not the actual files that are stored on your computer.
If clearing the list doesn't help or it causes Firefox to hang or crash (or if the Downloads window is already empty), you can manually clear the download history, as follows:
Open the Firefox profile folder (see the linked article for details).
Close Firefox completely (if open).
Delete (or rename) the file downloads.sqlite, which stores the downloads history in Firefox 3 and above. It will be regenerated when needed.
Note: You should also delete the downloads.rdf file (if it exists). This file stored the downloads history in older Firefox versions and is no longer used.    
If clearing the download history resolves the issue, you can set Firefox to not save a download history in your "Privacy" options for History. Click "Tools -> Options -> Privacy" and set "Firefox will:" to "Use custom settings for history" and then uncheck "Remember download history". However, this will automatically clear the Downloads window, leaving it empty after each download is completed. As an alternative, you can set Firefox to clear the download history whenever you close Firefox:
Under "Privacy / History", select "Firefox will -> Use custom settings for history", then select "Clear history when Firefox closes", click the "Settings..." button and select "Download History" in the "Settings for Clearing History" window.
How to clear the Firefox cachehttp://support.mozilla.org/en-US/kb/how ... efox-cache