Smasung Galaxy Bluetooth has some issues with conneting/disconnecting, any solutions?

pm.

Basically, I have a Renault Trafic with a bluetooth kit, and for the past few months when I first get in, the bluetooth syncs ok, then when i get out and back in the van, the bluetooth fails to sync correctly. It will strangely sync and stream music (even though it was synced to the ipod) but if I attempt to connect the phone, it takes ages then connects briefly before disconnecting. If i turn off bluetooth then on again it willl work fine.

I had decided this was possibly an issue with the bluetooth on the van 'handshaking' or whatever it be called. However, we just bought a new Mondeo which has bluetooth, and my phone is a constant battle to get it to work, when it syncs and connects, it immediately drops out again, like the van. It also refuses to show a phonebook. But, like the van, if I reset on/off the bluetooth it works ok... I have now concluded it must be an issue with the phone. Is this a known issue? Is there a possible resolution? It's driving me bonkers restarting the bluetooth everytime I enter and exit the vehicle.