Satellites Disappearing?

[asdf]

I downloaded Celestia couple of days ago, and I've been downloading some add-ons since then. At first, all the satellites worked as they should. After some time, I noticed that MIR had in some way disappeared. When I press "go to" when the MIR is selected, it goes to the right place and I think it also stays on its orbit, so the camera doesn't just stop there or anything. But when you move the camera around, it doesn't move around the (disappeared) satellite as it should, instead it just looks around statically. (Well, if you've ever played first person view games, you know what I mean.)
Just a while ago I also downloaded some add-on satellite (orbiting the Earth too) and it has just the same problem as the MIR.
All the other satellites work perfect.

It could be possible that this isn't even a bug at all, maybe I've just messed something up. As you may have noticed, I'm new to this.

Oh, and I do have the ambient light on, so satellites being totally dark shouldn't be the case.

OS: Windows XP Home Edition
Graphics card: Sapphire Radeon 9600 256MB

[granthutchison]

I suspect it's because you're looking for Mir after it has deorbited.
See the FAQs, question 20.

Grant

[asdf]

Thanks, problem solved. Kinda odd, because I were pretty sure that Celestia was using real time all the time. I did find it a bit strange to see MIR orbiting when it should've already been gone, though.

The add-on satellite doesn't still seem to work, though? Maybe it's its own bug, because as far as the readme file says, it should still be orbiting the earth even now. Doesn't seem to work even if I set the time ~2 years after the launch. Oh well, it's not that important.

[JackHiggins]

Which other addon satellite isn't displaying? It could be some other problem if you can't see it only 2 years after launch...