I have changed nothing since... many months ago.
Perhaps it's a server issue? But even then, I've not experienced any forum slowdown.
What I have noticed, however, is Firefox becoming considerably slower and slower over time. I don't know if it's got some kind of memory leak or something but I've found that the longer I leave the browser open, the more sluggish it becomes (especially with my 8 tabs always open, with this forum, youtube, facebook, gmail, hotmail, and whatever else I'm browsing).