Oops, I was wrong.

I deleted all of the ballpark image files, re-pasted them, re-pasted the .dat file in my league, and the images showed, with one exception: Rangers Ballpark. Must be because I'm a fan.
I didn't see any other posts with this particular issue. I may just re-install everything and start over to see how it goes. Probably won't get around to it for a few days though, so if anyone has any other ideas, lemme know.
It must be fantasy ball - my Rangers made it past the Division Series!