1997 - Windows 98, HP 4000 printer drivers assumed you had the floating point libraries loaded into windows, and just dynamically unloaded them whenever they felt like it. So, everything would work fine, until you did something that had to compute the page dimensions (and thus use floating point).

Forcing the loading of the floating point libraries fixed it, but it took months to track it down.

It turns out it was an optimizing compiler that HP didn't properly set the options on, in their make setup.