**System Information**
Archlinux
Nvidia 7900GT
**Blender Version**
Broken: Blender 2.69 Release (from arch repos)
**Short description of error**
Rotating and zooming in the 3D view causes viewport render to give incorrect results for volumes.
**Exact steps for others to reproduce the error**
Based on {F35823}
1. Enable viewport rendering (Shift+Z)
2. Rotate view and adjust zoom
3. The volume will be rendered incorrectly. This can be proven by disabling and re enabling viewport render without moving the view, the result will be different.