Are you saying that you changed the class name from "annonstext" to something, and that caused the problem to go away?
If so, I would be very surprised. In general, ad blockers don't rely on the hosting site flagging the ad in some way. If they did, webmasters would simply make sure that they didn't do that. After all, they have a vested interest in their ads showing up. Rather, the ad blocker uses an internal list of ad-serving sites to determine which ones to block.
As far as I know, the only way to change the behaviour of an ad blocker is to edit its blacklist and/or its whitelist. It would be up to the individual user to do that.