Adding Category destroys post formatting?

Hi – I just added a category to my blog, called “Palm Blogging”. When I went back and edited posts to add that category, I now find they format very strangely – no headline, no edit links, etc.

If you go here you can see what I mean, the first post is fubar, later posts are correctly formatted: https://www.lornitropia.net/?cat=5&submit=GO&paged=4

If you go here, you can see the category by itself: https://www.lornitropia.net/?cat=34&submit=GO

What the heck is causing this??