Tol tell you the truth even if it "saw" it - it could crash the desktop manager. There are several Blackberry Forums with this on it indicating there is trouble specifically with Windows 7 and blue tooth - coming from the desktop manager.
Mine did crash it... but to get it to "see" it I hit something like "Manage connections" (Upper right of the DM) and "added" device - which I am sure you have already done.... just keep doing it - a lot of times I had to just pound on the thing... restart the computer - you know the drill.
In the end though... sometimes you just have to wait until they update the DM.
Unless somebody has some troubleshooting I haven't heard which I would be all too happy to try.
So, right now I am just waiting for the update to the DM.