FAT filesystem Panic on USB Flash Drive

I'm getting error messages like this when I try to plug in my USB flash drive (it's a PNY model). I'm using the 760 kernel. Basically I can't write to the drive any longer and some directories show up as broken symlinks. This used to be stable and the drive writable.

usb 1-6: new high speed USB device using ehci_hcd and address 5
scsi5 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 5
usb-storage: waiting for device to settle before scanning
Vendor: Model: USB DISK 2.0 Rev: 1.13
Type: Direct-Access ANSI SCSI revision: 00
SCSI device sdc: 507904 512-byte hdwr sectors (260 MB)
sdc: Write Protect is off
sdc: Mode Sense: 03 00 00 00
sdc: assuming drive cache: write through
SCSI device sdc: 507904 512-byte hdwr sectors (260 MB)
sdc: Write Protect is off
sdc: Mode Sense: 03 00 00 00
sdc: assuming drive cache: write through
sdc: sdc1
Attached scsi removable disk sdc at scsi5, channel 0, id 0, lun 0
usb-storage: device scan complete
FAT: utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
SCSI device sdc: 507904 512-byte hdwr sectors (260 MB)
sdc: Write Protect is off
sdc: Mode Sense: 03 00 00 00
sdc: assuming drive cache: write through
FAT: Filesystem panic (dev sdc1)
fat_get_cluster: invalid cluster chain (i_pos 0)
File system has been set read-only
FAT: Filesystem panic (dev sdc1)
fat_get_cluster: invalid cluster chain (i_pos 0)
FAT: Filesystem panic (dev sdc1)
fat_get_cluster: invalid cluster chain (i_pos 0)
FAT: Filesystem panic (dev sdc1)
fat_get_cluster: invalid cluster chain (i_pos 0)
FAT: Filesystem panic (dev sdc1)
fat_get_cluster: invalid cluster chain (i_pos 0)
[rlc@bobcp4 ~]$

Here is a directory listing:

[rlc@bobcp4 ~]$ ls -al /media/UDISK20
total 145536
drwxr-xr-x  11 rlc  rlc      16384 Dec 31  1969 .
drwxr-xr-x   5 root root      4096 Feb  5 10:59 ..
-rwxr-xr-x   1 rlc  rlc      93996 Feb  3 20:46 1.0.4.3.arm
-rwxr-xr-x   1 rlc  rlc        160 Sep 10  2003 appletest.htm
drwxr-xr-x   2 rlc  rlc       4096 Jan  3  2004 ATIRadeon
drwxr-xr-x   2 rlc  rlc       4096 Jan  9  2004 bafo_xp
-rwxr-xr-x   1 rlc  rlc       1568 Sep 10  2003 boblayout.css
?---------   ? ?    ?            ?            ? cbg54
-rwxr-xr-x   1 rlc  rlc     984823 Aug 11 21:23 CBG54_30_15.zip
-rwxr-xr-x   1 rlc  rlc        705 Sep 10  2003 Default.htm
-rwxr-xr-x   1 rlc  rlc   24265736 Aug 26  2003 dotnetfx.exe
?---------   ? ?    ?            ?            ? F-Prot
-rwxr-xr-x   1 rlc  rlc     340798 Oct 17  2003 GCE-8400B103.ZIP
drwxr-xr-x   2 rlc  rlc       4096 Mar  9  2004 Microchip
?---------   ? ?    ?            ?            ? MomStuff
-rwxr-xr-x   1 rlc  rlc     133413 Feb  3 19:14 ndiswrapper-1.0.tar.gz
-rwxr-xr-x   1 rlc  rlc         64 Aug  2  2004 secretwpakey
-rwxr-xr-x   1 rlc  rlc  111366152 Aug 26  2003 setup.exe
?---------   ? ?    ?            ?            ? sp23085
-rwxr-xr-x   1 rlc  rlc    3320291 Aug 11 21:21 SP23085.exe
-rwxr-xr-x   1 rlc  rlc     441571 Jun 28  2004 tbl2SignsVariants.txt
-rwxr-xr-x   1 rlc  rlc     441571 Jun 29  2004 tbl2signvariants.txt
-rwxr-xr-x   1 rlc  rlc       1227 Feb  1 20:39 testrules
?---------   ? ?    ?            ?            ? WesternDigital
drwxr-xr-x   2 rlc  rlc       4096 Aug  1  2004 WN-WPCI Driver and Utility
-rwxr-xr-x   1 rlc  rlc    7561216 Aug  1  2004 WN-WPCI-Web-Update-v1.1.exe

--Bob Cochran