I don't know yet whether this is a problem with OSX 10.9 but I am unable to read the cards in my MBA after installation of 10.9. Any solution for this yet?
Are they NTFS formatted? I am having trouble with flash drives that are NTFS formatted. I use the free NTFS-3G software and am guessing that's the issue. One post here seems to echo that sentiment:
Also, found these Apple support posts where people indicate their problem is solved with NTFS-3G and Mavericks
I was having a similar issue - this helped me: http://www.youtube.com/watch?v=nbc0l-t3f1Q