Ok thanks to kwag for his guidance, althought he didn't told me how to do it, as morpheus did, he only shows us the door and we open it and enter, i finally made perfect cuts with bbmpeg, keeping audio in sync, an with the size i wanted.

With my movies cutted i finally erased all the ripped movies i had on my HDDs and released about 30 GB for getting new ones ang making others with new high quality templates.

Thanks master kwag!
DaDe.