When I'm trying to record greetings on the embedded voicemail, it just hangs up after the bip. I checked with system status and it says that my sd card is full. I don`t have any users with messages and no greetings recorded. If I put the card in my laptop it says i got over 50% free. I recreated the card and it solved the problem for a few weeks but then it came back. Anyone got any ideas?