Did you disable the popup windows message that reports errors?
My comment was serious. How is Newsbin supposed to know that the rars are going to end up corrupt when the PAR file says they're ok?
Lets say it downloads everything, validates or repairs the files and the PAR file says they're perfect but, they won't unrar (it'll say as much in the logging tab). What then? It reports this error in the logs and in the popup window.
I noticed that Newsbin fails to do anything when an archive is corrupt and par2 files will not detect it or fix it. Here lately U4A has had a lot of corrupt uploads and par2s can't fix it.
You're sure this isn't just your PC?
PM me an example and I can try it, nothing too big please. 4 gigs is about my limit.