Whenever I try to use coverflow with .psd files, I get a message saying "This layered Photoshop file was not saved with a composite image"

I went the photoshop file handling preferences and checked icon, full size, mac thumbnail, win thumbnail and always maximize compatibility, but it doesn't seem to work...I still get that say message...ny ideas why?

How big is the file? I've had issues on occasion where if the PSD was around 70 mb or larger it wouldn't render in QuickLook. A smaller size version worked just fine though.