I have the same problem.  I try to use the proxy function of HTTrack, and it
gives me the IPv6 address  fe80::d1d6:d857:b728:bbb6%13 and port 8080.  When I
use the ipconfig /all command on the DOS command prompt, the IPv6 address
fe80::d1d6:d857:b728:bbb6%13 shows up.  I know that this is my WiFi's IPv6
address.  When I put this address into Internet Explorer's proxy address, IE 9
will not save it.  So IPv6 address is incompatible with IE 9.  When I used
Firefox's proxy, the IPv6 address was accepted and HTTrack's proxy function
captured the URL.  I think HTTrack should use the regular IPv4 address or give
the use a choice between the two.  I think the port number should be
configurable rather than hard coded at 8080.  I could be running another
server listening on port 8080.