I'm sure it's been figured out but I had two unknown devices showing up and Win 7 couldn't find them and install them automatically. I tried the original Jlmicron drivers but the stock Mini 9 nor the Mini 12 Vista drivers would get rid of the "unknowns". I then went to "Devices and Printers" and the Mini 9 was showing up with a warning triangle. I clicked on it and let Win 7 troubleshoot it. The solution came back with a link to Dells download page for the right driver. I thought that was pretty amazing. I was having trouble trying to figure it out since the SD card drive was working with the default Win 7 drivers. All is well now.
910,Black, Win 7 RC1,64gb Runcore SSD, 2gb Ram, 32gb SDHC Cls 4,B-tooth,1.3Wb Cam, Sprint Touch Pro on Verizon
XPS M1330, T9300, 4gb DDR, 128gb SSD, 128mb Nvidia, LCD Screen, BT, Wireless-N, Soundblaster (320gb HDD w/ Windows 7)