Compresor has create your video ( MPEG2 ) and audio files … those are the two files. I;m not sure how IDVD works , as we use DVD studio pro here. But I can give you this one hint that may help. When you drop that Video & audio file onto the DVD creation timeline, they must have the exact same names… not the file format’s , these will be different , but the file names must match exactly. Hope this helps.