Perhaps it's not a network issue; maybe your destination computer is missing some codecs.
I would suggest using a checksum tool (7zip has one built-in; Microsoft has the command line File Checksum Integrity Verifier, and there are countless third-party tools) and compare the hash values. If they match up on both sides, then the network performed it's job and your problem is on the remote host.
However, if you find that bits are in fact getting flipped between your two hosts with large files, then you could add the movie to a split volume archive, then transfer it in multiple smaller files.