I was reviewing a teacher's course materials and came across a PowerPoint she uploaded that was displayed by the document viewer. Some of the slides feature an unusual artifact in having the drop-shadow of the PPT text being displaced from the actual text. I downloaded the file and viewed it natively in PowerPoint -- these artifacts are not present, in fact the entire slide is in a different font (which could be an installed font situation, I know). I'm far more concerned about the drop-shadow issue. Here's an example (my red box highlights):

Has anyone noticed this before? Do we think it's an artifact of the Canvas conversion for display in the doc viewer? Is that a bug or just something we live with?