Using revisison 12723 (also happened in 12722) from SVN on an Fedora 8 Test 3 x86_64 I cannot enter terror missions at all.
When I get to a terror site I am asked to Cancel or Enter -- if I choose Enter the aircraft stays at the site and sometimes the screen goes black with only a crosshair mouse cursor visible and an FPS counter in the rop right corner.
It looks to me like the game just doesn't render the battlefield.
If I press ESC (if the screen went black) the game goes back to the Geoscape and I am then unable to touch the terror site at all (that is, I can get a summary but I can't "enter" it in anyway).
After some time in the geoscape the mission times out and a lot of people die.
