I downloaded 10 items and 9 of them failed "» Repair failed, not enough repair blocks (xxx short) " +/- a few hundred blocks. I took one of the items and copied the _FAILED_ folder elsewhere and ran the download again. Then manually ran Quickpar against both folders and Quickpar shows that each download is missing blocks in multiple places. But each individual _FAILED_ folder's rar files were corrupted in different ways (i.e. .r001 in folder 1 would be missing 5 blocks and .r001 in folder 2 would be missing 3 blocks).
I loaded the same download list in Grabit and it download successfully 10/10 with 0 repairs required. Both Grabit and SABnzbd both use the same drive for caching, extracting and saving.
It definitely seems to be the SABnzbd application (v0.5.0), I've wasted about 150GB of bandwidth today playing with different settings and haven't found anything that fixes it. So, today I uninstalled completely and re-installed with the Windows installer, used the default settings (minus save location) and downloaded a 15GB file, both times it was corrupted, both times QuickPAR showed that different files had differing numbers of missing parts. Grabit downloaded successfully with no repair required.
The issue started occurring roughly around the time I upgraded my Internet connection from 8Mb to 50Mb. I don't believe that is the cause (Grabit works), but I figured I'd note it.
OS: Windows 7 x64
Install-type: Windows Installer and Windows .Zip
Skin (if applicable): NA
Firewall Software: ESET SmartSecurity, firewall disabled for all attempts.
Are you using IPV6? No
Is the issue reproducible? Yes, SABnzbd is practically unusable on my machine currently due to this problem. Looking at my download list, it's roughly a 70%+ failure rate (where the corruption is so bad it cannot be repaired with the .PAR files).