Firefox 19 Beta Not Showing Up in Mac Notification Center

I'm using Firefox 19 Beta (fully updated) on Mac OS 10.8.2 (also fully updated). I recently reinstalled the OS, and before I had, I was using the same version of Firefox. Before the reinstall, Firefox was using notification center for all notifications. I used to have Growl installed, but uninstalled it after Firefox added Notification Center support. Now, after the reinstall, Firefox is not showing up under my list of Notification Center applications. Does anyone have any idea how to get Firefox to show up in Notification Center? I have googled around with no success.

Thanks for your help!