Download hangs at 99%
This usually results from the NAT router replacing legitimate data in your packets. When the packet fails the hash check, because the router scrambled it.
There are three ways of fixing the problem:
1) Do not run your router in DMZ mode, many routers seem to employ game mode-like mangling by default for DMZ-bound traffic. Instead, you should enable explicit port-forwarding on your router incoming ports.
2) If your router a Game mode option, Turn it OFF. If there is no such mode, this is not an indicator that your router isn't the problem.
3) Try connecting directly to the internet direct, bypassing your NAT router entirely to finish the last piece.
Certain D-Link routers have a known bug (specifically models DI-624, DI-624+ and DI-604) that can cause a BitTorrent download to get stuck at 99.x% if your computer is set as DMZ.
One other possible cause for a 99% download not completing
Every once in a while, someone does something a little foolish. They create their torrent including a file called thumbs.db. If this is the case, you won't ever have a 100%: this file is a system file and change as the system sees fit, so probably even the initial seeder doesn't have a 100%. However it is totally meaningless, it is a dynamic files that allows windows XP to show thumbnails. It should not affect the other files, and you should be able to use the files without a problem even though that one file will never download.
BiTorrent, torent, bit torent, bittorent, bitorent, downlaod music.