Unfortunately there's absolutely nothing we can do about it because it's in the hands on our host. As I mentioned to BuzzH privately after she sent me a PM a few days ago on this subject, something is apparently up with our host's MySQL database server. For example, the other day I attempted to backup the database three times but couldn't get past 50% before the MySQL server spit me out. And it took 20 minutes to get that far even though it normally only takes 5 minutes to backup the whole thing.
The forum's system is completely database reliant (as most forum systems are these days), so any problems with a databse server are going to affect it.
The really interesting thing is that whatever the problem is, it comes and goes. For instance, I was able to backup the database on the 17th in the usual 5 minutes. And at least 75% of the time the forum has been behaving normally for me. Maybe I've just had good timing.
Though that being said, the forum is definitely sluggish at the moment...