Has anyone had a weird faoult using Blackerry client on p990i and having constant voice breaks. When blackberry off no probs at all?

Have no problems with voice
Still having an issue whereby the Blackberry client disconnects when I am at home
It worked fine in France Belgium and Holland
Was Ok in Edinburgh and all last week in Iceland
Just doesnt work when talking to my local Cell
Must be the network not the phone
Wierd..