Aperture 2 and 1.56 images not showing up in iDVD6 on Tiger

Any thoughts about why images from Aperture 2 (same with 1.56) might not be showing up in iDVD 6 on Tiger? I can see the projects, but no images are listed under each one. iPhoto images seem to show up normally.

Other details - all files are on the MBP, a software update indicates nothing to download, I've got Pro Applications Update 2007-01 and Pro Applications Update 2007-02. iDVD came with the computer and I've not used it much (if at all)