Ipod troubles

Hello, i download music using vidtomp3.com. when i try to drag the music out of google chrome downloads to my itunes or ipod this message comes up: "Some of the files were not copied to the ipod because they cannot be played on this ipod". i have an older ipod touch 8gb and is up to date and my brother has a new one and for some reason he \is able to put the same music i downloaded onto his ipod while i cant, We share the same itunes. Also, he can only put the music directly into HIS ipod library, it never is able to upload into our itunes library. Help?