Hover summary not displaying description test on MOST stories.

for some reason, when I hover over the icons on most of my stories the "description" title, the description itself, and the "comments" title don't display. There's space for them, but the space is blank. The comments themselves do display. I have *one* story that actually displays properly, and I can't figure out what the difference is, and why it would work there and nowhere else. Any ideas?