I Don't and will Not use LW any longer for reasons that you are experiancing. The Later versions are nothing but Trouble.
I will suggest you use an older version that has proved to be the most stable versions ever. 4.12.6. or 4.12.3
OldVersion - Newer isn't always better !
Or as I said above, try Phex.
And again as I said above, Call RR and see if they will give you any Info on possibly Throttling or Capping Bandwidth.