When the download folder is set to an UNC path (for example \\server\downloads) the automatic PAR repairing fails.
When using an UNC path as download folder and file repair is started, the PAR2CMD quits immediately, and and error is written in the log.
Manually executing the par2cmd also fails with the same error as seen in the log.
After making a network drive mapping X: to \\server\downloads, restarting Alt.Binz and downloading a collections which needs repairs the PAR works!
Alt.Binz 0.39.9 on Windows XP SP3
