I'm using a MAC and Firefox browser with a Garmin GPSmap60cs and am only able to send (download) one cache at a time to my GPS. Even if I "check all" and click "download all" ,nothing seems to happen except I get an Excel spreadsheet. I can download one at a time to the GPS by clicking the small "send to GPS" icon on each caches line, but cannot download multiple ones. Is this a MAC issue?