Something you need to keep in mind. Even the high speed connections can offer slow uplds to others. Some people have many slots open & if there's many people uplding then their upld bandwidth gets shared around. eg: They might have 20 or 40 people uplding from them. Or else they are just miserly with their upld bandwidth.
Also keep in mind, even though the downld might say a T1 or T3 or cable connection, that might be the highest but the others might be dial up modem. Also consider that when downlding from many people, you are probably only getting a small fraction of the speed from each one.
Also keep in mind that there are other p2p clients out there such as Shareaza (RAZA) which utilise 2 networks. The other one they can only downld as fast as they upld so that's where most of their upld bandwidth goes. So for LW users, they often find such raza users may only offer from 0.1 to 3 KB/s.
Now back to your issue. You sound to be very well set up!

If you still have the search results up, what you can do is cancel the downld & reselect it from the search results. This sometimes breathes some life back into the downld. Also re-searching the topic or browsing the host can sometimes re-liven the downld. Sometimes downlds can stall.
Did you try a file from the magnetlink site:
http://www.magnetmix.com/video.shtml Here's an example of speeds you can get: Stief’s example:
http://www.gnutellaforums.com/showth...692#post138692 & just click the downld & LW will take over the downld. Tell us what speeds you get.
Have you seen this See the following link & follow all the off-shoot links to find hints & extra skills to solve your problem:
To continue files downlding (click on link)
One thought is your XP SP2. SP2 reduces connections. Some people have applied patches to increase this by about 4 or 5 times I think.