Trying to rescue data from a bad SD card

[Thorny]

On Wed, 04 Mar 2009 08:44:36 -0900, Damien Hull wrote:

>[...]
> [53778.934622] sd 25:0:0:0: [sdb] Device not ready: Sense Key : Not
> Ready [current] [53778.934639] sd 25:0:0:0: [sdb] Device not ready: Add.
> Sense: Medium not present [53778.934649] end_request: I/O error, dev
> sdb, sector 12496 [53778.934659] Buffer I/O error on device sdb1,
> logical block 538 [53778.934673] Buffer I/O error on device sdb1,
> logical block 539 [53778.934679] Buffer I/O error on device sdb1,
> logical block 540 [53778.934685] Buffer I/O error on device sdb1,
> logical block 541 [53778.934691] Buffer I/O error on device sdb1,
> logical block 542 [53778.934698] Buffer I/O error on device sdb1,
> logical block 543 [53778.934704] Buffer I/O error on device sdb1,
> logical block 544 [53778.934710] Buffer I/O error on device sdb1,
> logical block 545 [53778.938230] sd 25:0:0:0: [sdb] Device not ready:
> Sense Key : Not Ready [current] [53778.938247] sd 25:0:0:0: [sdb] Device
> not ready: Add. Sense: Medium not present [53778.938257] end_request:
> I/O error, dev sdb, sector 12496 [53778.938265] Buffer I/O error on
> device sdb1, logical block 538
> 

This looks very much like a hint to me. Did you by chance run a file
system check on the unmounted device? Don't know if that would help or not
but might be worth trying.