Oh I've seen more. That's because the tires are cheaply made and can't be balanced properly. My Conti DWS tires balance really well, and I remember I saw as little as one 2g weight on one of my rims.
Yeah, for some reason I don't like Nexen tires at all. So far best tires I've had are Continental Extreme Contact DWS but they have a bit soft sidewall for my liking.