please don't move this until there is an answer it's been driving us both crazy for the past few weeks

right, the mrs has got a sony ericsson k310i phone, and in the top left hand of the screen there is a red phone with a red arrow bouncing off of it
it's not the missed call icon because that's a U shaped arrow and no ammount of delving into the handbook or scouring the internet has revleaed what this mysterious icon is so any help in this matter would stop it bugging us so

i can't even show you what it looks like as the camera won't pick it up for some reason but it's a red reciver/earpeice from a normal old school rotary phone facing downwards with a red arrow boncing off of the middle of it like a tick

someone MUST know what it is