I have a single Cisco SPA 525G phone on my desk. If a call comes in, just one of the lights comes on and I take the call. My issue is that as soon as I hang up, the display says missed call. I did not miss any call. No other lights lit while I was on the call. Each time I answer a call it displays Missed Call as soon as I hang up. I've asked support for help on this issue for three weeks and they keep giving me advise that does even apply to my issue. Hope someone out there can help.