I've noticed a little quirk on one of my blogs. It seems that any post that starts with the letter 'W' in the post slug returns a blank page when in single view.
I've try different themes, deactivated plugins and optimized my database but no change.
And when I say blank, I mean blank. Looking at page source (FF) shows no text at all. IE shows "page not found". Yet I see it on the archives and home page.
If I change to post slug to read 'problem' instead of 'what-problem' everything is fine.
See this in action via archives... http://photojulia.com/navigate/