Shareaza

This is a peculiar situation.

I selected several files to download from a single source a while back. Most of them have some progress now, but after a network interruption a few nights ago three of them show "no sources".

It for some reason has not figured out that the source it's still (slowly) getting the other files from is a source of these three files as well.

How do I make it do so?

Given, say, the IP of the source.

I got a magnet link for one file while it was downloading, edited it to change the hash and the filename to those of one of the three files being interfered with, and tried "add source" and paste but the download button in the "add source" dialog didn't un-grey for some reason.

There really should be a simple way to say a particular IP:port has the file and just add that as a source, and have it query that source for the appropriate filename and/or SHA1.

Or else, any time it contacts a source that has a file you are downloading it should add it as a source for any other files it also has that you're also downloading.

Or maybe it simply shouldn't randomly forget sources that are clearly still valid sources for the files in question.

Don't know the answer to your actual question, but Shareaza will generally only try to download a single file at a time per source. And only allow a peer to queue for two different files, most other programs seem to allow you to only queue for one. So you are probably not losing any actual downloading as long as Shareaza sees the source for at least one file. Also by default Shareaza does not show all sources it knows, so unless you asked it to show all sources it is possible it actually does know the source for the other files and just doesn't show it.