Queued = your LW is too busy to handle the downloads.
It basically means you are downloading too many at once. The incomplete files will begin queued when you start LW up. Else, about once every 30-60 mins LW attempts to find sources for the inactive incomplete files aka "locating sources". If you have a lot of incompletes then some may become queued during this process.

MAJOR TOPICS for Upload/Download HELP is a good place to check for tips.

If you see a brick wall in front of the blue world icon at the bottom of LW's interface, then let us know & supply these details: System details - help us to help you (click on blue link)