Blue Zinfandel Enhanced theme post issue

On a regular post-based homepage for this theme, some posts bleed into others. Take a look at this for example:

Notice that the second posts is smashed into the bottom of the first post. The first post should end “With love, Daisy” and then on to the next post. But instead, the second post bleeds into it.

I’ve received a few emails about this from different users over the past year. How do I fix this?