NO need to call orbitz. You can find your will call number on Orbitz. Just click you upcoming vacation by your name on the top line of Orbitz. On the next screen click the date listed. Scroll down till you see your will call confirmation number which should start with 4 letters. It will be available within a few minutes after purchasing. Then go to MDE and add the confirmation number to the ticket section.
Interesting...my will call number was not the same as my MDE linking number (My Magic number). They did both start with letters but they weren't the same.