Turn off Private Browsing
iPhone/iPad users may also need to disable Private Browsing. For help disabling private browsing, read this guide: http://support.apple.com/kb/HT1677
If you are still having trouble after changing the settings as mentioned above please make sure you are using one of these supported Browsers.
iOS Safari 3.2+ Android Browser 2.1+ Dolphine Browser 1+ Chrome Mobile 4+ Firefox Mobile 18+