drpag, not sure what the sign in problem was. But sounds like you were trying to log into the beta forums & not these ones. That's a separate forum.
This will commonly happen with video files. Often because you are downloading via someone else's incomplete file you are waiting for the last part from them until they finish downloading the file. In many cases the person with the complete file is not online on the gnutella network at same time as you are.
Best options I can think of are:
(1) Use the search function to try to find more sources for the file. Then also use the Get More Results option by right-clicking the search result tab.
(b) If you see the folder icon showing you are presently downloading the file & your download has not started to continue, then cancel your download & reselect from the search result that has that 'in download process' icon.