When you download anything like that, use a program to calculate and verify the MD5 hash is correct. If it isn't, then the download has become corrrupted.
You can get Nero to verify the data on the disc has been burned correctly, but I only know of doing this at the end of the burn itself, as part of the whole operation.
And really you should have just expanded the original thread with your post here
Edit: I guess a mod did just that
Also, where have half the posts gone? This thread's a bit of a mess now.