CDRLabs.com

I backup some of my movie dvds, since I sometimes feel scared to stratchh and destroy my own dvds. Well I use dvd decryptor to rip the dvd and then dvd shrink the dvds. Well on of my movies, everything is perfect, all the menus works, everything. Of some other of movies, the menus dont seem to work, when I select stuff, there seems to be a small delay before the actual menu item is selected if selected at all. What am I doing here. I dont rip the dvd in iso format, just file format. I use nero to burn my dvds.
Thanks