Trouble animating the scale parameter

[Jeff Davis]

I have a .psd file in my timeline I’m trying to push in on by scaling from 100% at the start of the clip to 110% at the end, about five seconds later. The .psd is the only media on the timeline during this period. Instead of a smooth push, however, the image stays at 100% for the first four frames and then visibly jumps to 110%. I say “visibly” because the parametric value increases smoothly from 100% to 110% over the duration of the clip, as it should. My program monitor is set to High Quality Playback, and this problem persists even in the rendered file. What might be causing it?