tyler@tobe ~ % sudo fsck /dev/sdb1
Password: 
fsck from util-linux 2.20.1
dosfsck 3.0.11, 24 Dec 2010, FAT32, LFN
There are differences between boot sector and its backup.
Differences: (offset:original/backup)
  0:eb/00, 1:3c/00, 2:90/00, 3:4d/00, 4:53/00, 5:44/00, 6:4f/00, 7:53/00
  , 8:35/00, 9:2e/00, 10:30/00, 12:02/00, 13:08/00, 14:20/00, 16:02/00
  , 21:f8/00, 24:3f/00, 26:ff/00, 28:44/00, 29:02/00, 32:bc/00, 33:35/00
  , 34:77/00, 36:ce/00, 37:1d/00, 44:02/00, 48:01/00, 50:06/00, 66:29/00
  , 67:61/00, 68:23/00, 69:43/00, 70:65/00, 71:53/00, 72:44/00, 73:20/00
  , 74:50/00, 75:4c/00, 76:41/00, 77:59/00, 78:45/00, 79:52/00, 80:20/00
  , 81:20/00, 82:46/00, 83:41/00, 84:54/00, 85:33/00, 86:32/00, 87:20/00
  , 88:20/00, 89:20/00, 510:55/00, 511:aa/00
1) Copy original to backup
2) Copy backup to original
3) No action
?