Sony Ericsson S710a

I have some cheap-o generic USB bluetooth adaptor which works great with my Moto V551, Nokia 6820 &6620, but won't even begin to look at my s710a (although I can use the phone as a remote still) using the SE software. I want to be able to sync my contacts and load songs via bluetooth but I can't get it to work. I'm beginning to think it's my crappy adaptor. I'm using XP Pro SP2. Unless anyone has some troubleshooting recommendations, which adaptors are working for you? Thanks all!