GPS off?

So I just got a new mobile gps for my car. Boy do I like it. Except for one small problem. My house is not where GPS says it should be.

So I just checked it on to or three items. They are were all wrong in town. Then I travel 70 miles away it is all perfect. So I am assuming the software is messed up. OR worse yet somewhere big is messed up

Have a super super day.