G1100 Router not handling static routes properly

I've noticed that the G1100 router does not properly handle static routes.  If I create a static route to a different network segement the IP header in the Ethernet frame is improperly modified, substituting the router's IP address as the IP source.  This should not be the case.  The IP source should remain as the original IP source and only the Ethernet source should be modified.  Otherwise the receiving endpoint has incorrect information as to where the packet came from and cannot return traffic.