[whpalmer4]

How long ago did you first use OmniGraffle on this machine? There's a 14 day trial period, after which you'll need to talk to Omni. The "too many users" doesn't apply to your demo case -- the case it is referring to is not getting a license because all of the license keys available on a machine have already been handed out, but that is effectively the same as not having one in the first place, such as only having an expired demo.

This past year, visitors to Omni's booth at Macworld could get a card with a coupon code for a one-time discount on software purchases. Wouldn't surprise me at all to learn that they had done something similar at other times. There's an educational discount, too, if you qualify.

Your understanding of the license terms is the same as mine. One user, many computers, or one computer, many users.