So you chose "Mass Storage" in settings? And once you connected, pull down the drop down men you, press USB, and then press the "Mount" button?
Mine worked just fine on WinXP and Win7 64 bit once I enabled mass storage and then confirm "Mount" each time you connect.
If I've helped please click "Thanks".
Sig. Upd. 4/1/13 --Samsung Galaxy Note II w/ CleanROM ACE--
Previous Phones: SGS 3, Galaxy Note, Samsung SGSII, Motorola Atrix, Samsung Captivate- Perception ROM, ATT Tilt2- Energy ROM, GTX/CHT, July 21, 23121, HTC Fuze, ATT Tilt, HTC 8125