speaking of dodgycoder...i liked his not on bug category higgs bugson:
Higgs-Bugson - a hypothetical bug predicted to exist based on a small number of possibly related event log entries and vague anecdotal reports from users, but it is difficult (if not impossible) to reproduce on a dev machine because you don't really know if it's there, and if it is there what is causing it. To find these you will need to invest in a Large Hadron debugger. by [runrunraygun]