In a forum (android-hilfe.de/) I have read that only the older batches to May / June 2012 function.
Now we there often posted much crap. But now seems to be some truth, because other customers have the same problem.
On Win7 PC, the card works at 100% - whether FAT32, exFAT or NTFS.
So wait until the problem is solved.
UPDATE: Nov.2012
Jelly Bean is going fine now!