weird MBR report from fdisk

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

I was given a 2GB flash drive.  MacOS X Leopard is happy with it; it
let me create a file on it.  Vista can see the file; so can Ubuntu.
But NetBSD thinks the MBR is, shall we say, unusual:

# fdisk sd0
fdisk: Cannot determine the number of heads
Disk: /dev/rsd0d
NetBSD disklabel disk geometry:
cylinders: 500, heads: 8, sectors/track: 32 (256 sectors/cylinder)
total sectors: 3948544

BIOS disk geometry:
cylinders: 500, heads: 8, sectors/track: 32 (256 sectors/cylinder)
total sectors: 3948544

Partition table:
0: Novell (sysid 104)
    start 1936028272, size 1851859059 (904228 MB, Cyls 
7562610/3/17-14796434/7/3), flag 0x6e
        PBR is not bootable: Sector 1936028272 is unreadable (Invalid argument)
1: unknown (sysid 121)
    start 1330184192, size 538976288 (263172 MB, Cyls 5196032-7301408/0/32), 
flag 0x79
        PBR is not bootable: Sector 1330184192 is unreadable (Invalid argument)
2: DM6 Aux3 (sysid 83)
    start 538989391, size 1398362912 (682794 MB, Cyls 
2105427/2/16-7567782/3/15), flag 0x20
        PBR is not bootable: Sector 538989391 is unreadable (Invalid argument)
3: unknown (sysid 73)
    start 1394627663, size 21337 (10 MB, Cyls 5447764/2/16-5447847/5/8), flag 
0x7e
        PBR is not bootable: Sector 1394627663 is unreadable (Invalid argument)
No active partition.
Drive serial number: 745239401 (0x2c6b7369)

But -- it can do things with it:

# disklabel sd0
# /dev/rsd0d:
type: SCSI
disk: USB DISK 2.0    
label: fictitious
flags: removable
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 8
sectors/cylinder: 256
cylinders: 500
total sectors: 3948544
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0 

4 partitions:
#        size    offset     fstype [fsize bsize cpg/sgs]
 a:   3948544         0     4.2BSD      0     0     0  # (Cyl.      0 -  15423)
 d:   3948544         0     unused      0     0        # (Cyl.      0 -  15423)
disklabel: boot block size 0
disklabel: super block size 0
# mount -r -t msdos /dev/sd0a /mnt
# ls /mnt
.Spotlight-V100 .Trashes        ._.Trashes      XX

Is fdisk confused?  

                --Steve Bellovin, http://www.cs.columbia.edu/~smb