I had the same question as you gmp as I also did a manual install because of a dodgy internet connection. There is, in case you missed it, an "update" option when you click the Sonar Platinum tab.
When I go to Command Center it doesn't recognise that I have many components already installed (indicated by red lights) to the left of the name.
Is this part of the same "bug", because I didn't install Cakewalk originally from Command Center?
If so, what are my options to ensure I keep my drives "lean"?
Thanks