Err not sure just venturing a guess... but if someone keeps doing it then the mods can remove their posts and as such the count for that post. But closed posts can't be modified/deleted so the post count can't be removed? Just a wild guess... you'd have to post this in EDMW to find out for sure :bsmilie:
Isn't the +1 supposed to be a sign of support for the previous poster or the thread before the thread gets locked? Some sites you can rate the posts and set the threshold level so posts with low points don't appear.
I think the reason posted by Gymrat76 is the most valid.
+1 before lock is used to alert the Mods of a potential problem thread as it will bubble the thread to the top (or near the top) of searches. Sometimes, due to the number of posts in the Forums, we do miss out potential problem threads and having someone bubble it up brings it to our attention.
Of course, there are other ways to alert us:-
a) send a PM to the Mods/Admin
b) Click on the Report Post button to send us an email