Needs more sources... even when there is a host or two
 

I recently tried downloading a large mpg file off of limewire and after a few minutes in only got to 2%, which is understandible. I pleaded with the host stay on for me to download it, but I didn't even get a reply and he soon left. Then, of course, the file said it needed more sources.

I ran a search for the movie every few minutes and it would come up in the results, which means someone is hosting it correct? Even when I told the file to find new sources, it still wouldn't start downloading, even though I could clearly see that the host was there again. I've had the problem before, but only when I'm searching for this particular type of movie.

If it is a quite popular movie, then there might be many people trying to download this file from that host, and depending on how many upload slots said host has allowed you might have to be patient until you move up the queue.
Another possibility would be that said host has blocked you (i.e. your IP) from downloading (for whatever reason).
So, try to search said file at different times, that might bring you new hits and other opportunities to get it.

And one more thing,.......please, do not double post here in the forums !
;)

Now it makes me wonder if I bothered him into blocking my IP address...

As I've said, it is just a possibility........
Due to the way the Gnutella Network works, you will "see" a new horizon of the network every time you reconnect to the network. That means, if you got only 1 or 2 hosts on a specific file when searching, there is a real chance of you getting more hosts for that file the next time you connect to the network and research.
Downloading files especially with only 1 or 2 hosts might need quite some more time than files with up to 10-20 hosts.
Just be patient.....;)