I encountered an error while editing a question. The error was:
"A question with that title already exists"
The only edit I had made was to change the case of some of the letters to make the question look less sloppy.
I figure there is a possibility that the designers did not intend for the title comparison to be case sensitive. That is, perhaps the error should have come up when the question was first created because a case-insensitive search would have flagged the duplicate?