Alan posted this tonight, "Printer and Plotter Bugs with Revit 2012". He's having issues with their KIP plotter and he reports that another London Revit User Group member is having trouble getting things out of their HP plotters.
Might have a quick read and weigh in if you can corroborate with your own issues. Serious enough that it might justify a early Web Update...if they can pin down the cause(s).
On another note (A flat), having trouble with your printer out-feed tray? Maybe this will help?
Saw it at a clients office recently, "Hmmm, finished stirring my coffee...I can recycle this!"