I found that I kept getting asserts all over the place when TEH MMORPG!!1 shut down, to do with objects not being found in my scene graph. Since I'm using an almost RAII technique for adding/removing objects in my scene, I didn't know where this problem was comming from.
Well, I found it on the way home yesterday. My scene graph is a std::set
So, I have to reinsert the object to the scene graph after I change it's position.
However, while I've been writing this, I just realised I'm sorting by X and Y position as well as Z, which is totally pointless. I'll change to to just sort by Z and pointer value. That also means I don't need to reinsert the objects when their XY position changes. Whoops. That'd explain the enormous drop in FPS when you start moving stuff...
In other news, I've started playing OpenTTD. I used to play Transport Tycoon Deluxe, but it won't work on XP. And OpenTTD has cool new stuff. The upshot of all this is that I don't get early nights because it's surprisingly addictive. "Oh, I'll just finish this one transport route". Followed by "Well, it's busier than I thought. I'll make the rail take 2 trains". Then "Oh, now I have more trains on it, I might as well visit a couple more stops", and it goes on like that.