plustek@linuxhacker.org

I had the same message and the driver won't load. As root I could start 
the driver with modprobe pt_drv and the scanner worked. The message does 
not matter: open as root the file 'modules' in /etc (for example: gedit 
/etc/modules) and write 'pt_drv' at the end of the file. Then save the 
file. Reboot.
 From now on you can scan (and any other user on your system too).

Good luck
Andi