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This has been happening at Yukupolis for quite some time. I've tried to figure this thing out unsuccessfully. It only happens in one forum and in a few specific topics. I even made 4 test topics to see if it would happen to them also but it doesn't.

First thing we noticed was that those topics jumped a page back. Say a topic has 59 pages, when you click on page 59, you end up on page 58 and then you have to click on page 59 to get to the end of the topic.
Now recently the members started to mention that those topics do not have the same amount of replies as shown on the forum page.

This topic for example:
http://chriswsplace.yuku.com/topic/2844?page=71

It shows 707 replies on the forum page right this second.
I see 72 pages (should be 71 if it matched the reply count) I just clicked on page 72 and got taken to page 71. I then have to click on page 72 where I see the rest of the replies. It has 711 replies, not the 707 that are showing.

Funny thing is that it only happens in one forum and in 4 particular topics in that forum. I can't reproduce the problem anywhere else, plus it doesn't happen all the time.
I tried hiding and deleting replies to see if maybe deleted replies were not being taken off the total count, but that's not it.