Bluetooth headset problems in Boot Camp

I have a mid 2011 iMac dual booting Lion and Windows 7 64 bit using Boot Camp.

When booted into Windows my bluetooth keyboard and mice work fine, but when I attempt to connect a headset (I have tried 2 different ones from different manufacturers) I get errors about could not load the driver.

I have attempted to reinstall the driver using the update driver method for both the headset and I have reloaded the Boot Camp drivers replacing the entire bluetooth radio drivers in the process.

I have also attempted to download and install the Broadcom drivers from Broadcom's site and the installer hangs on the Detecting Device step and never progresses even after an hour.

Anyone have any luck getting a decent Bluetooth stack loaded in Windows on the new iMacs? If so what did you do? What drivers did you use and where did you get them?