**System Information**
Archlinux
Nvidia 7900GT
**Blender Version**
Broken: Blender 2.69 Release (from archlinux repos)
**Short description of error**
File written by the file output node is different from what is seen in the viewer node:
- The viewer node sees the correct output, the output from the **Renderlayer** node.
- The written file appears to be black.
**Exact steps for others to reproduce the error**
Based on {F29783}
1. Render frame one
2. The viewer node displays the output of the mix node, which should be the same as the renderlayer node output. This works correctly.
3. The File Output node outputs a black image to /tmp/image_stacking_test/asdf/render0001.png