NOW, Newsbin wants THREE TIMES the download file size.
It can take as much as 3 times the set size in order to complete a repair and unrar. 2 times is the absolute minimum because for a short time the unrared files and the rar files will both exist on disk. If Newsbin has to do a significant repair then it'll be > 2 times before cleanup kicks in and removes the disposable files. Newsbin was fairly casual about disk free space before because I assumed (incorrectly as it turns out) that people would keep track of their disk space and seldom run low. I had one user though with 50 gigs of free space but terabytes of files in his download list. He was running out of space multiple times a day. So, now Newsbin is strict about free space checking.
I have 1.9TB free, so I don't think that is related to my issue.
The log file will always show errors if you're out of disk space. I'm not sure what to think about your issue. If it's just one set of files then it might just be a "posted wrong". The errors in your log are fairly weird.
If you restart Newsbin what happens?