I don't know why some people have so much trouble downloading things now. And I'm not getting shitty with you, so don't think that.
I've been seeing the files that won't download as well, everyone has (I'm using 4.12.6 Pro) but for me, using the All Types search & looking for songs via album title has given me good results. Otherwise I wouldn't tell people to do that.

When the helpers here give someone a serve, it's often because they have a history of being abusive, confrontational & disruptive on the forum (and via PM). This is not obvious to people reading the thread. We have many great people here (of course I'll defend them) who help a lot of people every day.

If you want to try other Gnutella clients...how about Phex or BearShare? They both have a section in this forum. If you did want to try BS, just be sure to use the 5.1.0b25 version, which uses the Bearstart utility. If you go to this thread, you'll find a link for download & more info
http://www.gnutellaforums.com/showthread.php?t=53386

*One thing you could try is deleting your LW preferences folder. I'm not saying it will fix your prob with seeing so many undownloadable files but if you want to try it, it can't hurt. It's up to you. Points 2 & 3 below have instructions. If you've used old versions of LW you may have a folder in either location, so check both.
Fixes for LimeWire