Itunes Problem- please help.?

Ok, downloaded the new itunes,i redeemed at �25 itunes voucher on itunes, i bought 3 films, waited for the to download, then when i re-opened itunes it said that i had to reinstall the programme because some important software was missing. I repaired it, and it loaded again, now when i go to sync the films onto the ipod touch its saying it cannot find them, and i go back to where i started, Please help, It's my brothers birthday present and i dont want him to be disspointed.