im not sure but tftpd may use a differnt protocol to ftp. i maybe be wrong on this. i havent tryed to use tftpd on knoppix.

it looks like it is http://packages.debian.org/stable/net/tftpd

try using this from another machine.

in cmd type

Code:
tftp iphostname GET certainfile.txt
you can transver up to 16mb at a time.