I have installed the IVT BlueSoleil driver that comes with the bluetooth usb drive & it is connected to my phone. But PC suite do not connect to my phone.
If you have only installed the PC Suite from the CD attached to your phone package go for an update at http://www.nokia.co.uk/A4222001# and load the newest version of PC Suite. Old versions Of PC Suite did not understand any emulated devices connected to USB ports. There is Connection settings where you can select most suiteble device for your link.
I used to have the same problem with an iR-dongle too.