In previous versions, if Gnucleus couldn't connect to a host for downloading a file, it would add the file to the pending list. This was a win, because it often happened that the connection would succeed on a later retry. (Direct downloads, and
occasionally pushes too, if the retry happened after a search.) 1.4.3.0 just gives up. Bummer.

Would it be possible to restore the old behavior, or add an option for it? Failing this, where can I download 1.4.2? I don't see it on SourceForge.

It only retrys if the host was alive. If your the hosts in the download list dont even respond to a connection attempt, there is no point in retrying that host. If all the alternate hosts in the list are the same way, gnucleus wont bother retrying.

Failure to respond is often a transient thing. If a host doesn't respond the first time you request a download, that doesn't mean it isn't live and won't answer later. But Gnucleus will now give up on it. Also, I've seen some clients fail to send a complete HTTP response if they are busy, and Gnucleus appears to consider this to be a connection failure. It isn't, since the host is live, and Gnucleus shouldn't give up on that host.

Gnucleus used to have the best download retry algorithm around. Not anymore.