Does size really count?

[oldshepp]

I am a newbie, so forgive me for my ignorance, but I was of the belief that the smaller the movie - the better the chance of dvdxcopy backing up on one disc. That doesn't seem to be the case.

Example - "Rugrats in Paris" only 75 mins long, but dvdxcopy is not interested in copying main feature to one disc.

Why is this so? Spirit is a longer movie but the movie fits on one disc easily.

Any suggestions please. My kids are hammering their movies and I haven't backed them up yet !