I'm exporting a Magic Bullet Looks project from After Effects and when I render the clip the exported quicktime movie is split. Top half green, bottom half rendered. (see attached screenshot). I'm totally blundered on this one.

Help!

I've had something similar happen to me as well, except it is more of a flicker then a split, but this only occurs when I right click on my edited clips in Premiere and goto replace with After Effects Composition or if I simply copy and paste my Premiere timeline into After Effects. The only solution for my problem is saving the After Effects project, closing it and reopening it.

For your problem though, have you tried getting updated drivers for your video card? Also try to export a couple PNG/PSD frames just to make sure it's not your Quicktime Codec that could be screwy. Also don't know if this would cause it, but make sure your fields are set properly (ie if you shot progressive, set it for it under the File->Interpret Footage or right click on the file in your project window).

I have the same issue and I'm wondering if anyone has an explanation or solution?

It looks like a field order, interlaced, progressive confusion.