Oh and yet another thing. LimeWire hosts (in opposite to some other vendors) value the busy bit in your query replies. When your host says it's busy another LimeWire client will give your host a lower priority when trying to download a file that you have but that others have as well.

If you want to know more about how LimeWire handles uploads and about what might be wrong, you can download the newest beta which comes with some nice statistics.

By the way, my client receives an upload request every other second and my upload queue is never empty.