A dynamically linked After Effects composition with transparency loses its transparency and appears opaque in Adobe Premiere Pro CS5.5.
Install the Adobe Premiere Pro CS5.5 (5.5.1) update, which fixes this bug.
If you can't install the Adobe Premiere Pro CS5.5 (5.5.1) update, you can use one of the following workarounds:
- Change the composition background color in After Effects to black (RGB=0,0,0).
- Change the Renderer setting in the Project Settings in Adobe Premiere Pro to Mercury Playback Engine Software Only.