Bizarre Notepad bug
Bizarre notepad bug that really exists. If you type a phrase consisting of a 4 letter word, then two three letter words, then a 5 letter word, save it, then reopen it, the text will be corrupted and unreadable. There is a claim that not all words cause this to occur. See the linked story for examples of what does work.
There was a great quote:
If Microsoft can't keep strange bugs out of Windows' simplest application, we'd better get used to the monthly security patch cycle.