Bluetooth headset cannot accept incoming calls with iPhone5

Hi,

I have paired my iPhone 5 via Bluetooth with my home phone which works as a "headset" for mobiles. Pairing was successful and I can make outgoing calls (i.e. initiate the call from the home phone which then uses the iPhone to make the call). Outgoing calls work fine, I can hear and talk.

Problem is when I get an incoming call and accept it via home phone, the iPhone picks up the call but does not route it to the headset. I.e. the call is connected but I cannot hear or talk with the headset/home phone.

Previously, I had another mobile (Blackberry) connected to the same home phone and it worked just fine so I am assuming there is a problem with the iPhone. Anyone else seen this kind of problem and is there a solution or is this a bug in the iOS (I'm on 6.0.2) that needs a fix?

Thanks for feedack!