Are you doing something dangerous according to Norton? If so, what?
Trainers work by injecting new values into the game's memory when it runs. When it does this, it overrides very specific variables that govern the player's stats to give you infinite money, health, etc. This is also the same technique that many pieces of malware work (imagine injecting information into the Operating System's special memory with instructions to open an elevated command shell). Because of this behavior, SONAR will detect the trainer in a false positive.
Unfortunately, trainers are not considered "high profile" enough to be given priority to be white listed in anti-virus updates. You have to configure Norton to whitelist all Cheat Happen's trainers or disable the component as a workaround (check your program's documentation for how to do this).
This is an expanded explanation of the one that can be found here (which is displayed in nice big red text on the post screen for a new topic so you can understand some frustration you may receive from other users and staff) : Link
[Edited by moderator Neo7, 9/10/2011 5:02:39 PM]
[Edited by moderator Neo7, 9/10/2011 5:03:33 PM]
I have never had that problem. Just because you got a virus, doesn't mean it was Norton.
ON TOPIC: Just tell Nortan to make an exception for the trainers. There may be a way to make it allow all of them, if not, then you will have to do it for each one.