Ask HN: Share your simple, time consuming bugs

I love debugging. It is an art: crudely so when we litter our code with desperate, sometimes vulgar trace statements; elegantly so when we employ careful step-through debugging.

Sometimes though, the bugs get the upper hand for longer than any of us would like to admit.

I think it would be possibly helpful and probably interesting to everyone, to see what kind of bugs have made HN readers believe that their machine acted out of disdain for the programmer attempting to assert control.