Are you resuming all your files when you start up LW? Some routers do have problems with traffic & if you resume all your incomplete files then that can cause unnecessary traffic. Instead, if you use the resume/find sources function to only apply it to 1 to 3 at a time.
This might also help:
Tip: Purge the Downloads Queue!
Also disable Ultrapeer capabilities under LW's menu bar, Tools>OPtions>Speed