We've not had any problems with our 2004 and haven't heard of any problems from other owners. Lucky you!
Do you ever have to do any extreme leveling? If you bought it used perhaps the previous owner did something extreme to get the frame out of kilter. Do you level the MH before putting out slides? Perhaps a twisting of the frame can effect the windshield. Does the windshield keep being replaced by the same facility?
Have you tried going on the Newmar forum and asking the question to Kountry Star owners to see if there's a problem with that year? Or iRV2 has a good forum, also. The factory is known for it's good service. Good luck to you.