I had ULTRA reader and I don't like it. It would create a drive entry in "my computer" and take a letter for every slot it had. Then, when you eject the card from any one slot, the whole collection would disappear until you reboot windows!!!
It sucked. I found that I can go to K-Mart, spend 12 to 14 bucks and get a reader that looks like usb flash drive, and use it when needed, and where needed.
Now, it shouldn't require a driver. Even in WinXP after SP2 the driver was present.
Where you plugging it to, is what matters, I think. My ULTRA didn't come with proper USB cable, it came with usb cable type A, which is supposed to be for external device. That one was hard to plug wrongly. How about yours?