Red 3 needs to be 3.0.5, follow the directions very carefully.
From the red install directions:
Be sure to follow the next two steps when launching FCP 5.1 for the first time, in
order to avoid a problem with the Boris windows not appearing. After the first time
you launch FCP 5.1, you can start the application as usual.
10. Press the Caps Lock key, and launch Final Cut Pro 5.1.
11. Immediately quit Final Cut Pro and launch with the Caps Lock key up.