problems with flash drive partitions

[JoeS]

My question is about partitions on flash drives.
One is a vfat filesystem and one is ext2.
cfdisk says that they don't contain a valid partition table.
They both used to auto mount and now don't.
They are both labeled.
What would cause the partition table to mess up?
Can I fix the partition table without erasing the disk?

I also have a problem with my ntfs partition:

Debian:~# fdisk -l /dev/hda1

Disk /dev/hda1: 20.0 GB, 20003848704 bytes
255 heads, 63 sectors/track, 2431 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x69205244

This doesn't look like a partition table
Probably you selected the wrong device.

Device Boot Start End Blocks Id System
/dev/hda1p1 ? 13578 119522 850995205 72 Unknown
Partition 1 does not end on cylinder boundary.
/dev/hda1p2 ? 45382 79243 271987362 74 Unknown
Partition 2 does not end on cylinder boundary.
/dev/hda1p3 ? 10499 10499 0 65 Novell Netware 386
Partition 3 does not end on cylinder boundary.
/dev/hda1p4 167628 167631 25817+ 0 Empty
Partition 4 does not end on cylinder boundary.

Partition table entries are not in disk order
Debian:~# cfdisk

Debian:~# cfdisk -P r /dev/hda1
FATAL ERROR: Bad primary partition 0: Partition begins after end-of-disk

[oz]

What would cause the partition table to mess up?
Can I fix the partition table without erasing the disk?

Try running the Parted Magic LiveCD and use the partitioner (gparted) to see how it sees your partitions. If the partition table is corrupted, you might be able to repair it using TestDisk which also comes on the Parted Magic liveCD. You'll also find a number of other useful tools on the disk that might come in handy in the future.