Windows XP does not read any card in my internal floppy + card reader

::WinXP Pro SP2 + TEAC FD CR07 Floppy + USB 2.0 card reader (internal)
on Asus P5WD2 Premium motherboard::

The floppy and card reader are recongnised by WinXP. Floppy works fine.
The 2 card reader slots get assigned drive letters properly. No drivers
are available and presumably needed for this device.

As soon as I insert any card (tried with CF and SD, mine and friends')
the LED on the device gets red and Win XP Explorer either gives me an
"<drive>:/ is not accessible. Incorrect Function" error or "Please
insert a disk into drive <drive>:" message.

No Nero InCD installed (just Nero 7 Premium, which I also uninstalled
just in case but no joy), no EasyCD, no Norton Antivirus (these are all
the common culprits reported in the articles I found on the net).

It seems to be the device is properly installed but for some reason
Windows XP does not recognise any memory card inserted in the card
reader slots. By the way, this is the 3rd card reader I'm trying on
this machine (thought the first 2 were faulty, apparently they weren't
unless this is just a very unluck coincidence).

Any clues on what to investigate, any help whatsoever would be greatly
appreciated!

thanks,
Pinelopi