im quite new to Linux but i do have some basic knowledge

i shaved down zipslack(slackware) to 60mb and installed it on a bootable USBkey (these things you can store data in when your on the move)

they key is is bounced on the scsi so the kernel sees it as /dev/sda

i partitioned the key into 2 partitions. one for the system and one for data (/home)

now the first partition is the boot partition, its using fat.
the second partition is empty atm. and it is formatted the exact same way.. fat

but i cannot mount the second partition. when i mount /dev/sda2 /mnt/usbkey it says sda2 is not a valid block device

why won't it mount the second partition?