Default Slow XDA using Screen Mirror and SmartST V2 with 6" Mon


I am using a O2 XDA II with backpack. I have the Navman SmartST V2 which I am trying to run on a 6" monitor using Screen Mirror program. The whole thing grinds to a halt. Picture transfers OK but will not run. Can someone help me . I think it needs more RAM or similar. I have a 256Meg SD card in XDA with a 256 Flash Card in the backapck.