OPML Comments are clever and tricky the way they work across servers. And everything is fine as long as certain characters don't appear in the titles of posts. For example, question marks.
The problem is the text of the title is not currently URL-encoded. I tried to do it as a quick fix and was thwoarted. But today, when I was working on Stats & Atts, I think I saw the reason why. The att that contains the title is not called title, it's called text. Title is the title of the outline. Text is the title of the node that's being rendered. Confusing? Yes!
Let's see if my theory is correct.
Here's a post that has a question mark in the title.