Originally Posted by Lord of the Rings

Stalled means at some point the file started to download but has since stopped. Whilst LW 5 may occasionally re-search itself, these are not full searches. And if you use the Fix Stalled option, I've a suspicion it only re-seeks the ip addresses it was previously downloading from.

So always the best answer is to re-search for the file yourself. ie: same way you searched originally to find the file. Chances are the user(s) you were downloading from are offline or changed ip address.
Perhaps 5-10 minutes after a search has finished, you can right-click the search tab & choose Find More Results from the sub-menu that appears.