would like to see this implemented in a future release as well :)

Actually, after diving in to the code again, I'm unsure about the flag-thing. Code (in class_dm_pm.php gets executed until the counters need to be updated [which is the latest command when saving a PM]). The query is correct (I've been scanning all SQL queries), the code runs through that query, but the user record is not updated...
And that's really weird...

I will answer you tomorrow.
I made some test today, but I need more time and want home now :D

Yes. What I wrote is nonsense :(
There is no any flag.
I fully agree with you words.

There real thing is here:

When some one uses 'Advance Edit' to change my post a get a PM about that and "Private Messages: Unread 1, Total 1." are updated.

When some one uses 'Quick Edit' to change my post a get a PM about that but "Private Messages: Unread 0, Total 0." are not updated! :(
But! When I check ANY PM in my Inbox folder and for example use 'Mark as read', then "Private Messages: Unread 0, Total 1." get updated.

I am trying to look throw it.

I get a good answer from vBulletin's support team.
Here it is:

When you make a "Quick Edit" only the changes of the post are updated at the server. Nothing changes with the user session because the page is not reloaded in the browser.

With the "Advanced Edit" there are several page loads. Each page load will update the user's session record.

That it.

Hi Maxim,
thanks for looking into it. So I guess there's no way to update the counters when a moderator edits a post via the quick edit?

can future versions have an option to exclude certain members from it...like exclude admin based on members ID?