You can use DVD Shrink to strip unwanted items from your dvd.

If you are only ripping your OWN dvd's you may need to remove the protection.
This is what I do...

Run Any DVD, it runs in the background to remove protection.
use Windows Explorer and copy the DVD to your hard drive.
Use DVD Shrink, load the files into DVD Shrink and strip out any features you don't want. This program will shrink a DVD 9 down to a single DVD 5.
Use Image Burn to burn the files to DVD.

Have a look at this site, there is a wealth of info....

http://club.cdfreaks.com/