People if you download off of newsgroups you MUST know what par2 files are and how to use them. They are not posted just for fun they are files that can fix rar files that are broken, most of the time NO FILLS are needed if par2 files are used correctly!
Here are some guides:
http://www.slyck.com/ng.php?page=6
http://usenethelp.codeccorner.com/QuickPar_Primer.html
I would use the QuickPar program to handle par2 files, HERE
LEARN HOW TO USE PAR2 FILES!!!