ALWAYS Chunk Filter issue

[seajunk]

I'm occasionally seeing the following message in the log when downloading episodic content:
[10:08:48] ALWAYS Chunk Filter: Chunk Filter Plugin HFC:Duplicate Detector Match:***.nfo

When it occurs its the second or subsequent episode of a series, never the first. It may happen a the start of download or some part through it. It can happen in the same newsbin session or a week apart.
The download obviously stops but i can override by downloading again while bypassing filters. The download and content are then fine.

Im not sure if its the post, the server or newsbin. Its more of an inconvenience rather than big issue at this stage.
Content is downloaded through newsbin search results window.

Newsbin 6.62
Usenetserver hosting