animated still frame...jerkiness???

OSX 10.4.3
Dual 1.8
FCP 5

I've imported a .psd file with plans to animate certain layers. When I try to scale things up, I'm getting a jerky move almost every time. Not with all layers, only a few, but I've been noticing this same problem on a few other projects I've worked on.

A simple picture montage was giving me the same issues a few weeks ago and I couldn't figure out why certain pictures were giving me a jerky move. It seems like for 1 frame it is interlaced and then immediately pops back into place.

Any help is appreciated.

Epp
www.eppicfilms.com

Did you de-interlace the still? Effects - Video Filters - Video - De-Interlace.

I've tried and still no luck.