Vista - Bluetooth Headphones Setup

Hi all,

Having some trouble getting my new Bluetooth headphones to work on my Vista
(Home Premium 32-bit) Laptop. The headphones are the Sony DR-BT21G and I am
trying to use them on my Dell XPS M1710 laptop. The laptop doesn't have
built-in Bluetooth, but I have a dongle that seems to work ok.

I have tried the headphones on my Brother's VAIO running XP and internal
bluetooth. They connected right away and give great quality sound when
listening to an MP3 in Media Player etc.

On my Vista laptop, the headphones are recognised (I am using WIDCOMM
5.1.0.2100 bluetooth software with my dongle) and when I enable them, a
little message pops up saying that audio will now be routed to the headphones
.... but it isn't. If I open up Media Centre, or any games, the audio still
comes through the laptop speakers. The only time I can get sound from the
headphones is when I enter the 'Sounds' option in 'Control Panel', select the
headphones and press 'Test'. This produces the correct test sound in the
headphones. All other audio seems to go through the laptop speakers

Anyone know what might be happening, or maybe you have these headphones on
Vista? Is there a Vista setting somewhere that I need to enable, as they work
great on XP. Or do I need to do something with Bluetooth drivers to make this
work?

Thanks for any help,
Cheers, THM