I got a RepRapDiscount Full Graphic Smart Controller from ebay. I have it all working but the SD Card part kinda... If I power the Prusa i3 up then put the SD Card in the slot. Marlin 1.0.2 does not see the card. If I leave the card in the slot, power down 10 sec, then power back up. Marlin 1.0.2 then does see the files on the SD Card and can print from it. Why can I not just pull the SD Card in and out like I see other youtude videos doing?