Why can't the LabQuest print to a HP Deskjet 6940 printer?

This is a known bug in LabQuest App 1.0 and has been fixed in new versions. This problem has been fixed in the new release of the LabQuest App, which is available as a free download at:
http://www.vernier.com/labquest/updates/

If printing problems persist, check to be sure you are using an appropriate USB cable to connect with a computer. You cannot use the cable that came with your LabQuest.