The situation with add-on bluetooth adapters in the UK is a strange one, a lot of the cheaper adapters available are physically tied into the Bluesoliel software, which is provided for free with the hardware.
Where the problem with this occurs is when you need to update the
drivers for a new OS, it's like the printer situation under Vista you neeed to buy the software package to get the
drivers.
They sometimes have released a cut down version for free but the full package is commercial
On a side note I have such an adapter which I gave up on about a year ago - this now works OOB with build 7100 except for the lack of one particular
driver from for my phone - and that may well be Sony