IIRC, your kernel would need to have been compiled with scsi support. The Flash Card would be /dev/sda1 or /dev/sdb1 or so on.
You'll need to try mounting these devices until you find the correct one. If you don't have any other firewire hdd, USB hdd, USB thumbdrive etc. connected, usually your card reader would be /dev/sda1. If it has multiple slots for different cards e.g. CF, SD, MS etc, then each slot will be assigned its own device. One would be /dev/sda1 the next will be /dev/sda2 and so on.
If you can't find yor device in this range, then your kernel probably doesn't include scsi support or the scsi module is built as seperate module but is not loaded.
I don't use default kernels, so I don't really know if mandrake provide the modules or provide it built-in to the kernel.
hope that helps.
<b><font color=red>"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."</font color=red><font color=blue> - Benjamin Franklin</font color=blue></b>