It is suggested to keep your radio on your device up to date because it often gets bug fixes that allow you to get better reception, battery life, and less dropped calls.
Lets update the radio:
First Download the latest Radio Here to your /sdcard
Rename ota-radio-2_22_19_26I.zip to update.zip
Press Home + Power while booting up your device to enter the recovery console
Press ALT-S to update the radio
The device will reboot serveral times, once your are back in the android os, power down the device then boot up!