Link error with geometry shader (driver bug?) - opengl

Question

I have a GLSL program that works on some machines, but fails to link on on one particular machine. I suspect a driver bug, but hope that someone will recognize something I'm doing as being poorly supported, and suggest an alternative.
If I omit the geometry shader, the vertex and fragment shaders link successfully.
The error log after the link error says:
Vertex shader(s) failed to link, fragment shader(s) failed to link, geometry shader(s) failed to link.
ERROR: error(#275) Symbol 'gl_AtiVertexData' is defined with 2 different types between two stages
ERROR: error(#275) Symbol 'gl_AtiVertexData' is defined with 2 different types between two stages
ERROR: error(#275) Symbol 'gl_AtiVertexData' is defined with 2 different types between two stages
My code does not contain the symbol gl_AtiVertexData, and Google finds no hits for it.
The GL_RENDERER string is "ATI Mobility Radeon HD 4670", GL_VERSION is "3.3.11672 Compatibility Profile Context", and GL_SHADING_LANGUAGE_VERSION is 3.30.
I've trimmed down my shader programs as much as possible, so that they no longer pretend to do anything useful, but still reproduce the problem.
Vertex shader:
#version 330
in vec4 quesaVertex;
out VertexData {
vec4 interpolatedColor;
};
void main()
{
gl_Position = quesaVertex;
interpolatedColor = vec4(1.0);
}
Geometry shader:
#version 330
layout (triangles) in;
layout (triangle_strip, max_vertices=3) out;
in VertexData {
vec4 interpolatedColor;
} gs_in[];
out VertexData {
vec4 interpolatedColor;
} gs_out;
void main() {
gl_Position = gl_in[0].gl_Position;
gs_out.interpolatedColor = gs_in[0].interpolatedColor;
EmitVertex();
gl_Position = gl_in[1].gl_Position;
gs_out.interpolatedColor = gs_in[1].interpolatedColor;
EmitVertex();
gl_Position = gl_in[2].gl_Position;
gs_out.interpolatedColor = gs_in[2].interpolatedColor;
EmitVertex();
EndPrimitive();
}
Fragment shader:
#version 330
in VertexData {
vec4 interpolatedColor;
};
out vec4 fragColor;
void main()
{
fragColor = interpolatedColor;
}
Later information:
When I tried renaming the interface block VertexData to IBlock, then the error message talked about a symbol gl_AtiIBlock instead of gl_AtiVertexData, so that symbol name was a red herring.
If I don't use interface blocks, then the program links correctly. That's a bother, because I'll need to write the vertex or fragment shader differently depending on whether there is a geometry shader between the vertex and fragment shaders, but maybe that's what I need to do.