Tried to connect to the link provided, but no go.
Could you provide more details about your setup:
1) There seems to be 2 private network (192.168.0.0 & 192.168.1.0), is this correct?
...the problem is on the firewall script for a ftp server behind NAT
2) Are you applying the firewall rules at the router?
3) Did you try this?
... -j DNAT --to-address 192.168.1.6