While the attack has been mitigated, some people's web browser caches may be displaying pages that the web browser has saved on their computer. Virtually nobody should be getting the 5-second screen. You may need to clear out your web browser's cache in order to get full functionality of the site back again (info here:
Do You Have a Technical Issue or Question? READ THIS FIRST ). Then shut down and restart your browser.
If one browser works for you, but not the other, that's the likely cause.... the one that's not working right still has cached information saved that it's serving that is messing up the functionality of the forums.