Thanks for the info - I didn't realize that the bind to IP was for non-passive mode
I have a Linksys BEFSR41 and it is set up as per you note I have a range of ports forwarded and these mach the passive range in flashfxp.
I have actually just switched to using the port triggering feature in the linksys firmware and triggering off 1024-65534 from flashfxp.exe.
This seems to work kick ass - I can now fxp through the router with flashfxp which I could never get to work before.