I am sure I don't understand the difference, if any, between Catch Up and
the Synchronization settings for each newsgroup. I use Catch Up each time I
have unread posts left over after downloading headers (300 at a time) from a
NG and reading those I am interested in. This happens often in the active
groups. It seems it takes a long time to do the Catch Up and reset the
unread post number and I have learned to live with that even though I would
like it to be faster.

I wonder if using the Synchronization Settings for each group would help
solve this problem? Exactly what are the Synchronization Setting for, or
better yet, what does synchronize mean in this context?

Thank you very much for your help on this.