While reading my friend's page, something throws a cog. Don't know what exactly, but I get approximately the first 1/3 of a page (it actually stops in the middle of an HTML tag, which is kind of entertaining.)
I hit "refresh".
Same page.
Some intermediate system between me and the other end has made the brilliant decision to cache the broken third-of-a-page, and I can't force it to uncache.
Who *buys* this software?
(Solution: add an extra GET parameter, thus making it a "new page" and dodging the cache.)