Thanks for the replies.
First of all, I wouldn't advise anyone to disable AV software in order to download anything, even from a trusted site. That's just asking for trouble.
Second, Kryo's clarification of Norton's reputation feature is well taken. However, I doubt there is anything such as a "better AV product". As review after review have shown, they all have flaws and can, and will, miss security risks. Norton certainly has it's share of problems. I am familiar with many of them. However, this was the first time I encountered this warning.
Thanks again for your input.