This was a problem with the 1.9.4 update that should be fixed in the
1.9.5 update.
Currently I've noticed you still can't import into a brand new cardset
(the cards won't show up), but if you create the cardset, save it (go
all the way back out to the cardset list page), and then go back into
it, it should import without a problem. This will be fixed in the
next update which will be submitted this weekend. I submitted the
1.9.5 bug-fix update to try to get rid of all the critical issues with
the 1.9.4 update (crashing when deleting cards, no backs to cards
during import, ect).
Let me know ASAP if you find any other bugs and I'll be sure to get
them in the 1.9.6 update.
Thanks!
Jason