Transmission has never shown Notification Center alerts on my Mac (running OS X Mountain Lion). I was only even aware that it supports Notification Center when I used a friend's computer and the alerts appeared.
How can I make Transmission's banners appear? All of its Notification Center settings are the defaults already. When I go to Transmission -> Preferences -> General it says "Notifications: Configure in Growl" but the button is greyed out. I do have Growl installed and running; is that the problem? How can I make Transmission use Notification Center rather than Growl?
To be clear: Transmission's messages appear in Notification Center, but the banners don't appear on download completion.