I had this problem with two different PCs both running Windows 7 64 bit. After struggling for some time I solved the problem by installing new drivers available on the Broadcom website.
www.broadcom.com/support/bluetooth/update.php
Download and install the updated Bluetooth software for windows. Problem solved. Windows 7 and Norton system maintenance software do not behave well with Bluetooth adapters. The Broadcom solution has worked for me.
Cheers.