Vanishing Text

I hope it’s OK to get a little theme-specific here, but I’m not even sure this is a theme problem. A couple of months ago I wrote a post Titled Two-Wheeled Friends, and for some unknown reason, doesn’t show up properly as a preview/teaser in the Cutline or Thesis themes as when viewing it via monthly archives, a category or tag. (the full post views fine) I’ve got hundreds of posts, but only this one fails to display text when previewed. (you can see what I’m talking about here) Instead of displaying the first couple of sentences, all that’s shown is the letter “u”. I’ve tried making changes to the post, including removal of the image, but it doesn’t change anything. I can certainly delete the post and rewrite it, but I’d really like to understand what’s behind this. I’ve put this out on the Thesis forum but it fell with a thud, so here’s hoping that someone can help.