Talented Monkey: Thanks for your reply. I do seem to have solved the problem now.
I believe it was something to do with the FTP Program I was using to upload the files with. I normaly use Terrapin, but I thought it might just be a little difficult for my brother as he has never done anything like this before and I did not want to confuse him more than needed so I used the program called Flash FTP. My brother had a copy of this program so it seemed to be the obvious choice as I also have it.
When I used Flash FTP It caused the corruption of the files. But when, after I posted this thread, I tried again using Terrapin The files uploaded without any corruption.
I have now rechecked the site (after a couple of hours break) and find them to be ok, so I will have to tell my brother to get Terrapin and use that instead.
Once again I thank you for you time and response and pray I don't have any more problems with it.