Igo8 on din2 chinese navi system

I have on my 2din chinese no name navi original Sygic 10 .But i want igo 8 on it .So i made a sd card with iGO8 8.3.4-1.102680 with normal Igo skin on it runs fine but when i switch to radio i can not return to igo when touching the navi button.Anybody knows why this is.With sygic this is no problem .
Thanks.