In this theme the wrong images show up on the forums main page.
There are different images for a forum with unread messages and with all read messages, but those images don't match the explaining of the images in the footer.

Ok now an example:
In the News forum I have an unread message so it shows this image

but this image means that there are no new messages by looking in the register
No new post

In the Announcements forum I have no new messages so it shows up this image

but this image means by looking in the register it means that i have new messages in there
New posts


Check it and you will notice it is not a sessions bug in the forum. It happens always.

Mighty_Y