Personally I'm not sure what to advise. If you have problems downlding those magnet links or at low speeds then it very strongly suggests ISP intervention such as p2p bandwidth shaping. You could try connecting thru a higher port but it might not make a difference. Try connecting thru ports 49152 - 65535. A good one to try is 64049. ie: go to LW's menu bar, Tools>Options>Advanced>Firewalls & change the listening port to such. If possible also change the connection port to 64049

Otherwise try some other gnutella programs & see if you have the same problem; Just to check, you might try FrostWire or Phex to see if you have the same problems.