Sorry, didn't see this post previously. If you share same kind of files, this will assist in your searches.

Files that start & stop, doing a fresh search might help. With LW 4, you could cancel the download & re-choose from search results. It would continue from where it had previously stopped. Cannot do this with LW 5 /LPE however as cancelling a download will delete the incomplete file.

Check you are not being affected by firewall. LW's menu bar, Tools -> Advanced Tools, top left of screen will say if you are firewalled.