I'm seeing an issue in the HDR4392 version of Celestia. When orbits are turned on an odd shimmering occurs down the lengths of them, this is hard to see in still screenshots, but more apparent when animated. Using higher contrast highlights the problem though, which is seen as the odd glowing patches up and down the orbit line.
Contrast enhanced:
HDR4392 Orbit Issue
HDR4392 Orbit Issue
System:
Asus A8N-SLI Premium nForce4 SLI
AMD Athlon 64 X2 4200+
2xeVGA GeForce 7800 GTX 256MB
2gb Dual Channel DDR (400) 3200
Asus A8N-SLI Premium nForce4 SLI
AMD Athlon 64 X2 4200+
2xeVGA GeForce 7800 GTX 256MB
2gb Dual Channel DDR (400) 3200