Iam facing aproblem while trying to mount a 4GB SD card(High capacity) when formatted with a logical sector size of 512 which is always recommended.

I have formatted the card using a card reader and by issuing the following command on a linux PC : mkfs.vfat -I -F 32 -S 512 /dev/sdb

When i try to mount the same card on an ARM based proprietary board with montavista Linux running it issues a mount error:

FAT:bogus number of reserved sectors.
VFS: did not find a valid filesystem.

The command i have issued is: mount -tvfat /dev/mmcblk0 /mnt
Is there any restriction for 4GB SD cards by the mmc layer?

The same card mounts with out any errors if formatted with 2048 logical sector size.(i.e givig the -S 2048 option.)

Any help??