I have a AMD A10-7800 with integrated R7 graphics.... I disabled the on board graphics and installed a R7 240 Graphics card. When I pull up the adapter it says Radeon R7 Graphics + R7200 Dual Graphics?
Perhaps your motherboard is not allowing you to disable the integrated graphics if a 240 or 250 is installed. Honestly though you should return the 240 and buy a 260, the price difference is around $15 yet you gain nearly 4x the performance.