I am also having trouble and none of the solutions seem to work.
If I disable the 3rd party bluetooth the windows bluetooth stack does not work. According to Dell, the bluetooth hardware only works with the 3rd party software. When I strip the 3rd party software and search using the "add Bluetooth device wizard" it can't find it even though its right next to it. With the 3rd party software it can see it. I am using a Dell Inspiron E1505 and blackberry 8800 with latest OS and desktop software.