Well, I was up until nearly 01:00, but I finished the San Francisco DVD in time for Christmas. The first burn had something wrong with the menu screen; iDVD is incredibly picky about what file format you use. (PNG works, TIFF doesn’t.)
Another iDVD problem is that if you use the “automatically add slideshow to DVD-ROM” checkbox, then it often either crashes (OS 9) or locks up (OS X) during encoding. Solution: Add second copy of files to DVD-ROM section manually.