[Pan-users] Help understanding the unread articles count

[Tim Hogan]

I am looking for someone to help me understand the unread articles 
counter in the "Group Pane".  After I download new headers there will be 
a bold number next to each group that has new articles, say for example 
that alt.binaries.photos.original shows a number of 635 new articles.  
If I open the group and then go back to the group pane without making 
any changes , all of a sudden the new article count is down to 483.  
What happened to the rest of the articles?

Regards,
Tim