Just as a comment... sometimes resuming is the issue for people. If you tried xdcc with one file and it worked and you stopped part way through downloading it and then you tried resuming that file from dcc to see if dcc was working, you may run into problems for that reason alone.
I know little regarding routers as I don't use one, but I wouldn't think the port choice would affect how you download if you can use xdcc and not dcc. Not sure, though.
