Iridium has released firmware version HP21001 for the Iridium Extreme handset. The update provides the following updates:

• Added optional audible indication of network connectivity status changes. User-configured in Menu > Setup > Volume and Tones > Network Tone.
• Improved communication channel selection algorithm used when establishing a connection with the network in telephony mode.
• Added stronger validation checking of periodic radio calibration changes before storing to persistent memory in telephony mode.

The firmware file along with the instructions can be found by clicking this link.

Note: The firmware update utility is not compatible with Mac OSX.