diff -uprN util-linux-ng-2.16.1/shlibs/blkid/src/probers/vfat.c util-linux-ng-2.16.1-new/shlibs/blkid/src/probers/vfat.c
--- util-linux-ng-2.16.1/shlibs/blkid/src/probers/vfat.c	2009-08-21 15:59:30.000000000 +0200
+++ util-linux-ng-2.16.1-new/shlibs/blkid/src/probers/vfat.c	2009-10-01 21:05:26.000000000 +0200
@@ -18,6 +18,13 @@
 
 #include "blkidP.h"
 
+#undef STATIC_ASSERT
+#ifdef __GNUC__
+# define STATIC_ASSERT(e) extern char _dummy[(e) ? 1 : -1] __attribute__((unused))
+#else
+# define STATIC_ASSERT(e) extern char _dummy[(e) ? 1 : -1]
+#endif
+
 /* Yucky misaligned values */
 struct vfat_super_block {
 /* 00*/	unsigned char	vs_ignored[3];
@@ -45,7 +52,7 @@ struct vfat_super_block {
 /* 43*/	unsigned char	vs_serno[4];
 /* 47*/	unsigned char	vs_label[11];
 /* 52*/	unsigned char   vs_magic[8];
-/* 5a*/	unsigned char	vs_dummy2[164];
+/* 5a*/	unsigned char	vs_dummy2[0x1fe - 0x5a];
 /*1fe*/	unsigned char	vs_pmagic[2];
 };
 
@@ -58,20 +65,23 @@ struct msdos_super_block {
 /* 0e*/	uint16_t	ms_reserved;
 /* 10*/	uint8_t		ms_fats;
 /* 11*/	unsigned char	ms_dir_entries[2];
-/* 13*/	unsigned char	ms_sectors[2];
+/* 13*/	unsigned char	ms_sectors[2]; /* =0 iff V3 or later */
 /* 15*/	unsigned char	ms_media;
-/* 16*/	uint16_t	ms_fat_length;
+/* 16*/	uint16_t	ms_fat_length; /* Sectors per FAT */
 /* 18*/	uint16_t	ms_secs_track;
 /* 1a*/	uint16_t	ms_heads;
 /* 1c*/	uint32_t	ms_hidden;
-/* 20*/	uint32_t	ms_total_sect;
-/* 24*/	unsigned char	ms_unknown[3];
+/* V3 BPB */
+/* 20*/	uint32_t	ms_total_sect; /* iff ms_sectors == 0 */
+/* V4 BPB */
+/* 24*/	unsigned char	ms_unknown[3]; /* Phys drive no., resvd, V4 sig (0x29) */
 /* 27*/	unsigned char	ms_serno[4];
 /* 2b*/	unsigned char	ms_label[11];
 /* 36*/	unsigned char   ms_magic[8];
-/* 3d*/	unsigned char	ms_dummy2[192];
+/* 3e*/	unsigned char	ms_dummy2[0x1fe - 0x3e];
 /*1fe*/	unsigned char	ms_pmagic[2];
 };
+STATIC_ASSERT( sizeof( struct msdos_super_block) == 512);
 
 struct vfat_dir_entry {
 	uint8_t		name[11];
@@ -143,6 +153,10 @@ static int probe_fat_nomagic(blkid_probe
 	if (!ms)
 		return -1;
 
+	/* Old floppies have a valid MBR signature */
+	if (ms->ms_pmagic[0] != 0x55 || ms->ms_pmagic[1] != 0xAA)
+		return 1;
+
 	/* heads check */
 	if (ms->ms_heads == 0)
 		return 1;