There is a comment or two about this by the LW devs several years ago. There is a maximum allowable number of uploads to a specific host. Beyond this they receive a temporary ban. I can't remember exactly how it works except I think the ban period is for about an hour or two, if they are banned again it applies for the entire session. This was based on number of requests, I think for number of files. But also intended to prevent downloading of same file over & over by same host.

What I can find after a search: http://www.gnutellaforums.com/open-d...reeloader.html, . . http://www.gnutellaforums.com/open-d...tml#post213603, . . http://www.gnutellaforums.com/limewi...tml#post334712

The following quotes are from 3.9.5 Beta & 4.1.5 Beta discussions:
LW 5 used a variation of this system which in my experience seemed to be highly buggy with hosts being banned for almost no apparent reason. Also, this would remain in RAM memory so if you restarted LW5/LPE, the host could still get banned immediately they attempted to resume their download from you. I've seen a host get banned for trying to download a single file on many occasions. sighs. I suspect this system was based on number of request messages, not number of files. Seemed to be different logic used compared to LW 4 (& LW clones).

I think this auto-banning was also in defense against some of the older clients, which would not respect the usual or later rules of download engagement. And some clients like Morpheus would ignore queueing, somehow bumping hosts out of the queue until they reached no.1. But I'm talking about 9-10 years ago.

A preventative measure to stop this happening to you if downloading is not to queue up too many files to download from each search results. Choose 1, 2 or 3 at a time. In that way, if you are not sure they are all from same host you should not suffer the auto-ban issue. From SBerlin's description, sounds like you should wait a period of time before selecting another file to download from same host.