I'm trying to create a DVD with DVDA2 which will contain both 4:3 and 16:9 clips. In DVDA1 in optimize i could set them manually.... But now in DVDA2 i can't....
In the Optimize window, select a media file on the left. Then, on the right, go to Video->Recompress Settings. Set Aspect Ratio to whatever you want. Change it to 4:3 or 16:9 as necessary. You can do this for each file, and it will not change settings for the other files.
Or choose "From Project" to use whatever the default for the project is (under "Project video format" at the bottom of the Optimize window).