Nope, I don't think it's a problem in usb stack. What's the size of the other usb stick which mounts fine? What's filesystem on your SanDisk usb stick? FAT or FAT32? The stick that mounts (also a SanDisk) is 512 MB and FAT32. (I think I may have reformatted it myself on WinXP at some point in time.) The SanDisk U3 stick (1 GB) that doesn't mount is FAT. -jr