It's not always easy to determine the why's about why somebody's speed starts to become irregular or goes flat. It's not necessarily their set up but possibly the sources they'e downlding from. I think Leeware gives a good description about this here: Their Upload Settings (click on link) Sometimes if I'm downlding a file & it continually drops to 1 or zero KB/s then I will Stop it. Then re-select from the search results. Further details HERE.

After LW has been open for more than 30 mins do this test: Bug Report instructions & sample image Is it True/False? If false then there is something blocking your uploads. It's a good idea to share at least 50 files & have your Chat enabled so it's easier for people to browse your files. Some people get suspicious & if they can't browse their files they think they are Freeloaders alias "Leechers"! And apparently may stop their uploads or even block their isp using filters.