formatting a SD card

Hi,

  The SD card I'm using in my SL5600 has got corrupted somehow.
ls /mnt/card gives Input/Output errors as does any file system function
(mkdir, touch etc).  I have tried reformatting with mke2fs but this fails
with errors ('Device size reported to be zero'), the widowmaker app, and
opie-formatter, but I think they are just shelling mke2fs and fail.
fsck and e2fsck fail saying the superblock could not be read.

I need to low-level format the card, does anyone know how?

fdisk does'nt work on sd cards

thanks

  Ian