ipad mini not printing wirelessly over AirPrint

i have an iphone 4, iphone 5, ipad 2, macbook pro and now ipad mini. i can successfully print wirelessly to my Epson WF 2540 from all devices except my ipad mini. when i try and select a printer it says no devices are found. it is operating on OS 6.0.2 which is the same as the iphone 5 and ipad 2 which have no problems finding the printer over wifi. anyone have any advice? not sure why this isn't working..