Due to a bug in the official Catalyst 7.11 drivers (internal version: 8.432.0.0), I used the Catalyst provided by HIS (internal version: 8.430.0.0).
The official Catalyst 7.11 have a bug in GLSL when the shader has to deal with more than one dynamic lights. In the surface deformer benchmark, there are two dynamic lights.
The following image shows the bug in action: