Ahhh this stuff can do your head in sometimes
can't it...
When you click on a magnet link limewire then has to go and search for that particular file and cross your fingers those hosts are online, if you get the Need More Sources after the count down select the Find sources option it will search again...
If it doesn't come up with the hosts that more than likely means they are not online at the moment...
As for the other problem
..I honestly cant tell you why...