solution!!!Open firefox, go to TOOLS > OPTIONS > DOWNLOAD ACTIONS > VIEW AND EDIT ACTIONSThen look for ZIP FILES, then REMOVE ACTION for ZIP flies.Then try downloading file from AVSIM, it should ask what you want to do with the file, at this point select SAVE TO DISK, and REMEMBER THIS ACTION, and all should be well.PS I'm not shouting, the capitals are just for clarity....honest!! I noticed that my setting for ZIP files were all correct for save to disk, but still it was trying to open in browser, only a full delete of ZIP file actions cured the problem. Hope this helps!Gary