Not always easy to upgrade if you have plugins and stuff from older versions in there... plus there's no reason a new version would solve the time outs we experience (they might though as I know absolutely nothing about SM forum software
), but it's more than likely down to hardware resources, or lack thereof... which could be a combo of a bad script or just simply traffic... which is why I'd close the entire forum to guests with immediate effect to rule this out (you could still alow bots to crawl and add to serp)