What do you mean it says they are connected. Do they say connecting for ages & then show Need More Sources, or are they showing downloading at 0 KB/s?

If the latter, then re-search their topics to find fresh sources. If you find them they will have the download icon next to them which is a yellow open manilla folder with a green arrow. So cancel file from download window & re-select to download. This often does the trick if the initial search doesn't help.

If the previous problem, then see Recognising fake files