we installed SX 200 ICP at a property around 1 year back. But its strted acting weird from last 1 month. every now & then few extensions will ring & if u answer there is no one on the other side. There is no pms & its a small prperty of just 30 rooms & the system is also never switced to auto attendant. I tried reinitializing last time & reprogrammed the system but it still continues. Any guess what could be the problem ??? & also it happens on random extensions