I noticed today that in my development forum, it not shows the last user who replied metadata correctly when visiting tags postlist.
The wrong data is related to the latest user that reply into a post. With the next example you will understand the problem.
First you need to visit a tag, i go to visit this one: http://www.openconquer.com/beta/t/servidores-privados-de-conquista-2-0
You can see into the image:
Now check the discussion and the user who latest replied is different, check image:
Hope that i could explain properly. Maybe the bug is already reported, not sure.
Edit with another example:
At https://huddleberry.com/t/interests exists the post "Let me show you how to preserve tomatoes for a year!" with the real user who added a reply named "Mariam". In metadata the last reply username is "Ajayi", wich is obviusly wrong...
Seems that this bug happens in many forums, mine was runing latest beta 6.