Every time someone asks about adding additional DVD-ROM data to a video DVD, you have been providing those same instructions. Please stop telling people to use DVD-Rom (UDF). The correct procedure should be as follows:
On your hard drive, create a folder with the same name that you would like to give the DVD. In this folder, place the VIDEO_TS folder. Then copy the additional data files or folders that you want to include, but do not place the extra items in the VIDEO_TS folder. So if you want the finished DVD to be named DVD Movie, the folder would look like:
>any extra items
In Toast, choose the Video category and click "VIDEO_TS Folders". Then click Add, navigate to the folder structure you just created, and add the VIDEO_TS folder. Then click the Options button. Next to Video, choose Custom. Then enable the "Include DVD-Rom Content" checkbox and click OK. This will allow you to burn a video DVD along with the extra data. Compression can optionally be enabled to make the VIDEO_TS folder fit on a single layer DVD. You can't do compression with "DVD-Rom (UDF)".
However, there is one slight issue. The "Include DVD-Rom Content" checkbox does not work correctly in Toast 9, Toast 10, or Popcorn 3!! Despite checking the box in all these programs, the extra data files are not burned to the DVD. The exact same feature works correctly in Popcorn 2, so there is obviously a bug in Toast 9, Toast 10, and Popcorn 3.
Although I have submitted numerous tickets, Roxio's tech support has been completely useless. They refuse to acknowledge the issue or to even understand the problem. Instead, they keep posting canned, generic responses which have nothing to do with the original issue at all.
Continually telling people to use DVD-Rom (UDF) is not going to fix the issue. If you really want to help people add DVD-ROM data to a video DVD, then start demanding Roxio to fix the "Include DVD-Rom Content" option instead of continuing to post your inaccurate instructions.