dvd to dgp

Hi, okay so i bought a ndsl with r4 cart for my son last night and gaming is perfect. however im trying to get some vids on his card
and have reached a stonewall. i have a bunch of scooby doo dvds that i ripped to my pc hdd using dvddecrypter and are stored on hdd in iso format that i stream to his xbox via xbmc...now can i convert these 4.5 gig dvd.iso to .dpg format or am i wasting my time?
batchdpg gives errors, super gives errors, even tried i cheat xtra and fails...everything fails when trying to convert these iso to dpg.
I have the latest moonshell here but i cant even make a dpg.
what am i doing wrong?
please help me.

Tips:

1) Try converting a *short* movie clip before trying to do a full length film. It's going to take hours for it to convert before you will find out you have done it at a too high a resulution and it will not play in Moonshell, etc etc.
2) Try this guide to convert DVDs to .dpgs
3) Which *exact* version of Moonshell are you using? The latest is 2Beta 7, but it's pretty unstable. I would advise to stick to v1.71, which was the most popular.