I’m having similar problems in AE CS4. here’s the scenario importing AE generated stills into fcp 6.04.
AE save frame as…psd file – fcp will not allow it to import
AE save frame as…tga file – fcp will not allow it to import
ae save frame as…png rgb+a – successful
ae save frame as…tif rgb & rgb+a – successful
ae save as photoshop layers – successful
while the tif, png and psd layered files work fine and the alpha channels remaing intact, i am curious as to why it won’t import the composited psd file or targa images.