Apparently some crewmembers the other day refused to fly HZ-SNE because the GPS system on the aircraft was deferred. Although the aircraft is legal to fly, the company ops says the aircraft has to have a proper functioning GPS in order to operate in Iraq. This has been a problem with this aircraft every since DHL took delivery of the plane. Just last week a crew flying this plane strayed 10 miles into Iran because of the GPS. and Another crew was reported 25 miles off course returning from Kuwait. However maintenance refuses to do anything about it because there are still some crew members willing to fly the plane in order to keep the freight moving and DHL management happy