Problem: Matrox Millennium dual screen mode doesn't work with ArcScene
Some users have reported problems using ArcScene with a Matrox Millennium G450 graphics card configured for dual screen (dual-head) output. It's okay if run in 24-bit single screen mode.
Appears to be card/driver specific.
Solution or Workaround
If dual screen output is required, turn off '3D Acceleration' on the performance tab of the Matrox Display Properties dialog box. Otherwise, switch to single screen output.