The message box #wpf-msg-box does not scroll with the page as it does on your forum here.
This is not a huge problem, but if a topic is fairly long and then someone who is not logged in tries to post something, they may not see the message they need to log in or register since it is only appearing at the top...
Can you please take a look? The forum is:
I'm sorry but I have no clue. This is a CSS conflict with your theme or with some plugin. First try to deactivate all plugins, delete all caches and do Ctrl+F5 on front then test it. If it doesn't helped you should find some CSS specialist to solve this conflict.