First problem with encoding

[Glytch]

Recently I tried to encode Finding Nemo, but alas the quality was poor. I have done many other movies and the quality has been fine on the size of 700MB but this time I got poor results.

What could be contributing to this and how do I rectify it?

[Wolfman]

chek yur settings .. anim normally compresses better than anything else, maybe kept ac3 sound by accident? try again?