I keep getting that when I try to download a very popular movie. Although there appear to be nearly a thousand hosts apparently sharing the file. Every time I double click on the file, I keep getting "Awaiting Sources".

I mean, I'm sharing some very sought after files and a quick look at my monitor shows that people are clearly able to access them cos they're uploading like mad. Have I been blacklisted or something ?

A movie with almost 1000 hosts is very likely a fake, especially if it's a new release or really popular title

Search again, vary your search terms, try the All Types search. Stay away from files with lots of sources, go for a file with 10 sources or less, or those with a modem source.

For movies, always check a file before download with Bitzi. A file with heaps of sources but no Bitzi rating is often a fake.
How to use Bitzi

For music, try the tips in this thread
How to find music

And for some general info about these fakes
Info about fake files