www.sandisk.com SanDisk's flash memory drives won't work as IDE slave under Linux - the BIOS finds the drive okay - but when Linux boots it does fine the drive if it is a slave - does find the drive if it is set as a master
I do not currently see this hardware listed on the hardware compatibility list so it is possible that Linux itself is not seeing it because it does not yet support it. New drivers are being worked on all the time so you may see this become supported in the near future.