Premature wheel bearing failures.

I have owned a 2005 Dakota 4x2 for 3 years now and every 8-11 months I have to put wheel bearings in it,one side or the other fails, I think the failure is that its a 2 wheel drive with no axle stub in center of the bearing like on a 4x4 . but I keep replacing them under warranty don't seem to matter what brand I bought either.