Working with CS6 Dynamic Linking, I imported an after effects comp with vector-based images(text) into the premiere project, and layered it ontop of a video (for lower-thirds).
The AE animation has motion blur included, and an empty background (so the video can show through). But for some reason when playing back in premiere, the blurs show what looks like high-contrast outlines (orange bodies have very dark red outlines, black bodies have very dark black outlines) until the motion ends.
Larger screenshot of the issue: http://i.imgur.com/oKGTb.jpg
Render out an alpha-channeld movie in AE and use it in Premiere? You have two choices of the type you need: Straight or Premultiplied.
It's motion-blurred, which means the motion is fast, which means it doesn't last very long, which means it isn't that big a deal in my mind.
Editing programs favor straight Alpha, though if you use DynamicLink none of that should matter and the render use the correct native transparency in the comp. In your case it looks more liek you have a layer style applied and since they render after everything else, they do not behave correctly with motionblur. Substitute your drop shadow/ outer glow with teh respectivce normal AE effect and those issues won't appear.