**System Information**
All systems, all graphics cards
**Blender Version**
Broken: 2.76
Worked: never (as far as I know)
**Short description of error**
The boolean modifier, when in "union" mode (and I use quotes, because "union" mode is actually actually acting like difference mode should act displays both meshes when they are non intersecting. This means the boolean modifier is useless in many animations.
This "union"(difference) mode would be a very useful tool for various animations were it not for this bug.
**Exact steps for others to reproduce the error**
See the attached blender file
{F281106})