Start a whole new search for the files that are sitting in the download pane...sometimes a new search can kickstart a download. You can also right click on a search result > search more > get more results.
Or right click on the file in the download pane > search > search for keywords.

If the files have been there for ages & just won't do anything, it might be quicker & less painful in the long run to just download another version of the file (if you can find it).

It's up to you what you deem a waste of time...kind of depends on file size, how much of the file is downloaded, how hard the file was to find etc. Because the network's constantly changing as users log on & off, it's really hard to guess when or if a source might show up