I think I figured it out. I had to make sure that Riva was running, or minimized to the Tray, for the fan settings to be restored after resuming from sleep (S3).
So is there any way to have the new settings applied after resuming from sleep? If I put the computer to sleep, then resume, the fan goes back to default (loud) settings. This is on a HD4850. Any help would be a appreciated.