I believe I figured this out. I had included a customized version of the JQuery UI on Themroller. jquery-ui-1.10.3.custom. (or jquery-ui-1.10.4.custom).
This wouldn't have normally been a problem but it looks like there is a small error in the JQuery style sheet where it references an image. The background image used to highlight the active date.
They named the image I was using, ui-bg_flat_50_657A99_40x100.png but the style sheet references ui-bg_flat_50_657a99_40x100.png. The small "a" in the name of the image url should be a capital "A". So that causes the effect to break visually.
So this wasn't an issue with the WA files at all. But I wanted to post my finding here in case someone else comes across this problem, although this might be somewhat localized.
(Jason. If you haven't read my previous PM, please take a look at it for me.)