I've got a USB memory card reader, and an SD card (128Mb). DSL is installed on the hard drive.

When I plug in the reader, I get in dmesg:
USB Mass Storage device found at 4
...
sda: Unit Not Ready, sense:
...
sda : READ CAPACITY failed

Then a bunch of I/O errors....

I/O error: dev 08:00, sector 0
I/O error: dev 08:00, sector 16
I/O error: dev 08:00, sector 8
I/O error: dev 08:00, sector 24
...

Doing a
mount /dev/sda /mnt/sda

gives me
mount: relocation error: mount: undefined symbol: blkid_known_fstype

I've also tried with -t vfat and -t msdos

On my WinXP box, it's a FAT format. I also tried it as Fat32.

Any thoughts?

I tried a USB thumb drive, which works, then I tried the memory card again, and I see the device come up as sdb in dmesg, but I can't seem to fdisk it.
I try:
sudo fdisk /dev/sdb

but get:
Unable to read /dev/sdb