I know this is an old thread, but just figured out how to solve this problem. Dell has "graciously" deleted the correct driver from their download area (thank you Dell). Alas, IBM has come to the rescue. Download and install the Ricoh Media Card Reader Driver for Windows 7 (32-bit, 64-bit), XP - ThinkPad T431s Drivers at this URL --> http://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles/ghx101ww.exe
Once installed, the Media device will function as designed.
Kudos to IBM for helping out stranded Dell customers!