This isn't a bug report exactly, as rather an observation of an odd behaviour of GalCiv. It may or may not point to an underlying bug in the graphics engine.
I routinely monitor my GPU temperature. In idle, it is about 55°. Quite nice and cool. During gameplay, it peaks at 72°, usual level is 70°. Now, what is odd? The temperature STAYS at 70° after quitting GalCiv. It looks as if nobody told the GPU that it can stop processing. What is odder? If I start a different game (Neverwinter Nights 2 for example), just wait until their graphics engine is fully loaded and quit, the temperature on the GPU goes down to idle immediately. I mean, immediately.
Other games do not show this behaviour. Whenever I quit the game, GPU goes down to 57-60° at once. Only GalCiv keeps the GPU at 70° after quitting the game. And no, not for a few minutes, but for hours, until I either reboot or start-quit another game.
No bug per se, but odd enough that I thought I should share it with the developers.