While connected, the handset seems to stop transferring data.

This problem tends to manifest itself when signal quality is an issue. Users who are attempting data calls from inside of a building also tend to have this difficulty. When your call drops, look at the signal strength indicator in the upper left corner of the LCD on the phone and verify that your signal is in the range of 4 to 5 bars. If you are not getting 4 to 5 bars of signal, you may want to adjust your antenna to get a better view of the sky. If the problem persists, please contact the dealer through whom you purchase Iridium service. You may also want to verify that your connection is not spoofing.