"The best debugging story I ever heard"
From Twitter: http://patrickthomson.tumblr.com/post/2499755681/the-best-debugging-story-ive-ever-heard
So Storage Technologies sent out technicians. The technicians, despite their best efforts, could not reproduce the bug in test settings: this bug seemed only to happen in the middle of large print jobs. So, on the off chance that this was a hardware issue, they replaced everything they could - the RAM, the microcontroller, the disk drive, every conceivable part of the tape drive - but the problem kept happening.