I have two C2665DNF printers, in different office locations, on separate networks. Both have the same issue: really slow printing of large files (PDF, Keynote, PPT, etc.) ... it seems to work okay with Word documents, but anything that is 5MB+ hangs up the print queue forever. It prints about a page every minute, and if there are multiple copies it only prints some of the additional pages. I adjusted RAM to max (300MB) and cleared the memory using the maintenance settings, but no luck. I have also tried printing direct from USB with no improvement.