The slight bit of residual air underneath the cup expands and pushes itself off at altitude. Used to happen to me too. If you put it on carefully once you get up high it should never come off again until you take it off. ____________________________________________________________ Weight Loss Program Best Weight Loss Program - Click Here! http://thirdpartyoffers.juno.com/TGL2141/c?cp=TiGutgbr35H16mSOZK6r2QAAJ1A9mk8a0luj1TJO2sh3zRLgAAYAAAAAAAAAAAAAAAAAAADNAAAAAAAAAAAAAAAAAAAEUgAAAAA=
