Seems nzbs.org is having some trouble today, sending out empty nzb files according to sab logs and my queue showing two entries for that site looping forever between waiting for some time and trying to read the url. The log entry however does not show the full nzb source url, making it rather difficult to guess where or what the problem was in case I hadn't been "lucky" enough to be a live witness.
Empty NZB file index.php?action=getnzb&nzbid=REMOVED&i=REMOVED&h=REMOVED.nzb
No mention of nzbs.org anywhere; this type of url is probably generic for all newznab based sites. Please include the hostname part in the log entry for nzbs loaded from remote sites.