In Win500, are you just entering the new talkgroup and sending it to the radio or are you loading the software with everything that was previously in the radio, adding the new talkgroup and then sending the new load to the radio? The software is designed for you to have exactly what you want in the radio loaded into the it when you send the new load to the radio. If you just put in the new stuff, that's all that will be loaded onto your radio when you're finished.