Is your router a wireless one? If yes, then perhaps all the incompletes are sending far too messages thru the router & destabilising it. Wireless devices do not give reliable speeds, they will fluctuate. Try this Tip: Purge the Downloads Queue! (click on blue link). I'm guessing you may well have some fake files mixed in which make LW work harder.

Why would you need to pay for pro again if you only just bought it? Six months of updates. Just go to your Personal Pro download page, ... remember the one you used to download pro from. Bookmark it. You can keep a copy of your pro installer.