The thing is when you log off it clears your phone cookies so that clears your template choice thus serving your the default forum template....

best bet is to not log off the forum to keep the phone template

because eveytime you do logout you will have to click the giant iphone to get it back again... there is no way around this im afraid mate unless you go to the main page on your phone... Boxing News and then navagate to the forum via that navbar