
1. Some planets, not all of them, are flickering. Sometimes flickering disappears when zooming in or out
2. Some planet textures seems very odd, I mean they don't show all, just stripe around planet, moon etc.
My computer is 1,6 Mhz, graphic card is 3D Blaster 4 Ti 4600 and Windows XP. And there's now problems with speed in Celestia, I mean that there's no slowing or nothing like that, it works fine and smooth (except those problems).
And Celestia is that educational one.