Enhancements/Fixes:
– Improvements to voice calling to eliminate inadvertent voice calls defaulting to mute
– Improve stability, resulting in fewer occurrences of unresponsiveness
– Bluetooth support for mono headsets with the Sprint Visual Voicemail application
If you have been experiencing that pesky issue, I suggest you check for the software update via the Settings menu. The new software version you should be looking for is 4.5.1A-1_SUN-154_5.
Source: Sprint