Since upgrading to Alfred 2 I have not been able to launch Firefox by typing ff. I am able to launch Chrome with gc, Activity monitor with am, etc.
Typing ff just shows it as a search query:
Search Google for "ff"
Search Wikipedia for "ff"
I'm on 2.0.5 with 10.6.8, and have the same issue on 3 computer. Preferences are synced with Dropbox. Firefox is at 21 and in /Applications