The forums is working normally and the menus haven't gone away, so it's definitely something with your computer. Does that happen with every page you visit on the forum? Are you visiting from the same computer you normally to visit? Any changes to what you usually do?
I don't want to jinx things, but it looks to be back to normal again!!
I think it might have had something to do with the kids doing some homework on this computer as I was finding pictures of Vikings and maths problems where the sales horses pictures should be...!