How can I connect my Blackberry Storm 2 9550 to Apple iMac9.1?

I have a Blackberry Storm 2 9550, but I it isn't getting recognized by my Apple iMac9.1 computer running Mac OS X version 10.5.8 when I connect the Storm II using the USB cable that came with the unit. I want to sync my phone with my I-calendar but the computer does not recognize that the phone is connected. I used the disk that came with the phone to load the Blackberry User Tools and after checking for updates, I now have Blackberry Desktop Software Version 2.0.0 (build 65) loaded on my Mac. When I open this application, I am told to ‘connect your device to your Mac using the USB cable’ but nothing happens. ‘Finder’ does not show any Blackberry phone connection to the Mac. Do I have to activate something in the phone to allow it to be seen by my Mac? How do I make this connection?