w800 and TomTomGO

I've got a TomTomGo 700 and a new Sony Ericsson w800i.

The phone is great - amazing camera, BRILLIANT Walkman, great features. Thing is, it doesn't work 100% with the bluetooth features of the phone (handsfree calling, traffic updates).

I've tried Sony and TomTom but they both give the same "FO" lines. The forums also don't have any pointers.

Really long shot, but I don't suppose anyone on here knows why / how to fix?

Thanks

PS. I was simply going to watch for updates to TomTom and to Sony thinking they must know of the problem and one of them fix it soon!