Thanks for the reply, makes perfect sense. The other replies about using other than canon ink cartridges do not apply at all as these are the original cartridges. I will address the paper tray issues you described.
Our brand new MX922, is mixing blank pages in with other printed pages. I printed 7 pages yesterday and they printed fine with the exception that there were 4 blanks between the 2nd and 3rd page. What causes this?