Driving me insane (Master Collection Installation)

So I just got CS4 Master Collection from my company, and am trying to install it on my mac. I have previously installed the Flash and Fireworks trials, which have since expired. Now when I run the Master Collection installation, it won't let me install Flash or Fireworks. When I run a full install they aren't included, and when I try a custom install it won't let me check them. I've deleted the trials, and the obvious files associated with them. What can I do?