This may have been discussed here or elsewhere, but I don't even know what search terms are appropriate for this problem.
Problem:
I have a USB card reader plugged into USB5/6 on my mobo. When I plug a USB expansion card into USB9/10, the drives on 5/6 disappear. I can't find them in Device Manager, and there are no conflicts listed. When I unplug the card from 9/10, they return as normal drives.
Specs:
ASUS M2N-SLI Deluxe
AMD Athlon 64 X2 6000+ Socket AM2
I haven't done this before...please let me know if I'm missing any information that would be useful.