I get often hangs when downloading something on CVS version. LW seems to not try all available sources, so I kill the download, restart it in the Library and often by doing so or simply repeat a search to get more sources, the Gui hangs.
Here are the steps to reproduce: 1)start a search for something big. 2) download a file and let the search open 3) cancel DL 4) restart iit from Library 5) if it says DL failure (Échec de téléchargement in French): 6) right click on open search tab and select repeat search. (you might have to cancel and start a dl a couple of times before LW say dl failure)
Java sample:
hang 2
Ciao
Edit: Also LW doesn't remember sources when you cancel and then resume download from the Library. LW goes in need more sources even if it was downloadind seconds ago.