The air vent plugs have been removed from the cartridges. Also, the final print quality is fine according to the print quality diagnostic page.
Here is a link to a few pictures that illustrate the issue.https://drive.google.com/folderview?id=0BzWM0VheQZDyUDlTcm14cTltZW8&usp=sharing
The first picture shows a page after the printer has not been used for a few days. The next three pictures show the results of the 3 cleaning cycles. Then there is a diagnostic page after the cleaning cycles have completed. Finally, I print the original document again, and it turns out fine.