Using the resume function can be effective sometimes. However, it's much better to manually search for the sources! What's more, if you resumed a great many files, you'd find they'd all be queuing for much, much, much longer And it could well play havoc with LW's connection quality. Each one sends out a minimal search every few mins until it eventually gives up with a status of Awaiting Sources.
Here's some hints on optimising LW: A well set-up LW can start to automatically continue its dwnlding after it's settled down perhaps 2 out of 3 times you open LW.
Optimising LW & Maximising Uplds & Dwnlds A (1st post only) & also
Part B which is even better & last & least are
search & dwnld hints.