If it isn't, updating the firmware to the version that supports it isn't too difficult and is available from http://www.greamerica.com/support .
Also, if the system is rebanded, and any of the frequencies are between 851 and 854 MHz, and have a number 0 in the 4th decimal place (i.e. 851.02500), you'll need to use one of the programming software titles to enter the custom tables needed for that system.