Just last week my laptop was lagging out of nowhere and a printer spooler process took up 90% of my CPU..Look, I've worked in IT for close to 5 years now, and I can safely say that printers are, in fact, the spawn of Satan, and are here to make our lives miserable.
Don't trust them. If they say they are ready to print, don't believe them. If you have to print something before a certain time, do so hours, if not days, in advance. They can smell stress. If you need them at the last minute, they will fail you. It pleases them, somehow.