There are many technical reasons the board can be slow. It could be at the server, the DNS routing, or something on the users end. If the problem is at the server, the administrators of the Forum should get with the provider and see if they need to update the server software, purge some of the old unused files such as site images that are way out of date (backup files that are redundant.) Or anything on the server end that is not within the users ability to effect.
If it is a DNS problem, you may try to use a different DNS server. Such as Google DNS or Open DNS (I think that is what it is called.) A DNS server ranks websites and allocates resources to access those websites. The more popular the website, the more resources are allocated to the website. If there is ten million "calls" for a website a day, the DNS server connects to the website much faster than if there are only two hundred calls a day. There is just more resources allocated to the more popular websites. About the only thing you can do about that is to drive more traffic to the site so the DNS servers rank the website higher.
But, if the website is slow for a few days and then becomes normal again, the server provider probably has just done some maintenance on the site. All that stuff is done behind the scenes.
