I forgot to mention a few days ago that I figured out how to make my flashcard reader stable...

The problem was that while the reader was installed correctly and appeared to work fine for SD cards, when I put a CF card in it the system would lock up.

The solution was to leave the reader disconnected from the USB cable. To use it, plug in whatever card you need to read, plug in the reader to the usb cable, and the computer detects it and works perfectly. When you are done, eject the drive (although this does nothing obvious) then use the "unplug or eject hardware' icon on the taskbar to disable the usb card reader, then pull the cards out and unplug the usb cable.

A bit strange, but works fine for me!