Can't "Build" DVD in Encore CS5

Hi, I just downloaded Encore CS5 onto a brand spankin' new MacBook. I imported the usual MPEG2 DVD audio and video files into the project and placed them in the timeline. But I found that I could not assign any of the standard properties to the disc, such as First Play and Title Button. So I opened the project on a different computer (also a Mac, 2011 model), where I had zero problems. Now that the project was complete and all properties were assigned to the disc, I switched back over to the new MacBook and tried to just burn the DVD, but the Build button is greyed out and will not click. Anybody know what could possibly be wrong?

Thanks!