I've heard of others both having problem with Clearwire Broadband & also with NextNet devices used elsewhere. AFAIK all or almost all wireless devices have internal NAT firewalls.

jay173's advice is good. Go for a very high port. 49152 - 65535 are usually the best if there's any doubt about ISP blocking of ports. A good one to try is port 64049. ie: go to LW's menu bar, Tools>Options>Advanced>Firewalls & change the listening port. If still no good, then try changing the connection port also.

If you speak spanish then see http://forum.emule-project.net/lofiv...p/t109149.html
If you don't speak spanish, then see a note in english near the bottom of that link page. This was all I could find when I googled your device model number.

BTW jay173, that port 3045 is officially dedicated to ResponseNet. See http://www.iana.org/assignments/port-numbers & also http://www.gnutellaforums.com/showthread.php?t=24523

It really depends upon how an ISP is blocking p2p. They use many techniques. It may include blocking of ports, it may include special programs that detect p2p programs & stop them in their tracks, or they may dedicate them to a lower priority bandwidth whereby they get slower speeds; aka bandwidth shaping. Proxies may 'sometimes' prove successful in cases where an isp is blocking.