okey, I rebooted, then deleted swap.
next:
umount /media/mmc2
fsck.vfat -a -d /media/mmc2/ -u /media/mmc2/
mount /dev/mmcblk0p1 /media/mmc2
reboot


Now it works perfect, but I still don't know what it was. Btw, bug 2940 is not for me, 'cause I own my n810 more than 1 year.