I rather using a usb 2.0 card reader, but when I tried WM5torage and Card Export, I remember both of them worked a couple of times, but for most of the times I tried to use them I got the same problem as you, I think Card Export didn't work or even complain, WM5torage returned some error message.
Another strange thing, when they did work, I had to use the device, i.e. press the start menu, open an application, for the transfer rate to become acceptable! really weird, if I just plug in the device and let it alone it was slow as hell to browse or do anything else.
So I decided to use one of these: