OpengGL with Shaders. I'm stuck. Triangle with Buffer + not working shader.

Hi.
The rendering with shaders doesnt work (nothing on screen). But without it everthing is OK. I use simple custom vertex structure, buffers.

Vertex structure:

Code:

struct MyVertex
{
        GLfloat x,y,z;
        GLfloat r,g,b;
        MyVertex() : x(0), y(0), z(0), r(0), g(0), b(0){};
        MyVertex(GLfloat x, GLfloat y, GLfloat z, GLfloat r, GLfloat g, GLfloat b) : x(x), y(y), z(z), r(r), g(g), b(b){};
};

Triangle constructor and its data:

Code:

MyTriangle::MyTriangle() : mVertexVBO(QGLBuffer::VertexBuffer), mIndexVBO(QGLBuffer::IndexBuffer), mVertices(3), mIndices(3)
{
    mVertices[0]=MyVertex( 0.0f, 1.0f,-2.0f,  1.0f,0.0f,0.0f);
    mVertices[1]=MyVertex(-1.0f,-1.0f,-2.0f,  0.0f,1.0f,0.0f);
    mVertices[2]=MyVertex( 1.0f,-1.0f,-2.0f,  0.0f,0.0f,1.0f);
 
    mIndices[0]=0;
    mIndices[1]=1;
    mIndices[2]=2;
}

Shaders preparation:

Code:

bool MyQGLWidget::prepareShaders()
{
    QGLShader shaderVert(QGLShader::Vertex);
    QGLShader shaderFrag(QGLShader::Fragment);
 
    bool isCompiledVert = shaderVert.compileSourceFile(QString("../QGLTriangle02VOBSL/shader_vert.glsl"));
    bool isCompiledFrag = shaderFrag.compileSourceFile(QString("../QGLTriangle02VOBSL/shader_frag.glsl"));
 
    if(isCompiledVert && isCompiledFrag)
    {
        bool isAddVert = mShaderProgram.addShader(&shaderVert);
        bool isAddFrag = mShaderProgram.addShader(&shaderFrag);
 
        if(isAddVert && isAddFrag)
        {
            bool isLink = mShaderProgram.link();
            if(isLink)
            {
                return mShaderProgram.bind();
            }
        }
    }
    return false;
}

Not working drawing function: (with shaders)

Code:

void MyTriangle::drawBuffers(QGLShaderProgram& program)
{
    int vertexLocation = program.attributeLocation("in_Position");
    int colorLocation = program.attributeLocation("in_Color");
 
    program.enableAttributeArray(vertexLocation);
    program.enableAttributeArray(colorLocation);
    program.setAttributeBuffer(vertexLocation, GL_FLOAT, 0, 3, sizeof(MyVertex));
    program.setAttributeBuffer(colorLocation, GL_FLOAT, 12, 3, sizeof(MyVertex));
 
    glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
 
    program.disableAttributeArray(vertexLocation);
    program.disableAttributeArray(colorLocation);
}

Working drawing function (without shaders):

Code:

void MyTriangle::drawBuffers()
{
    glEnableClientState(GL_COLOR_ARRAY);
    glEnableClientState(GL_VERTEX_ARRAY);
 
    glVertexPointer(3, GL_FLOAT, sizeof(MyVertex), BUFFER_OFFSET(0));
    glColorPointer(3, GL_FLOAT, sizeof(MyVertex), BUFFER_OFFSET(12));
 
    glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
 
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_COLOR_ARRAY);
}

Shaders:
Vertex shader:

Code:

#version 410 compatibility
in vec3 in_Position;
in vec3 in_Color;
out vec3 pass_Color;
void main(void)
{
     gl_Position = vec4(in_Position, 1.0);
     pass_Color = in_Color;
}

Fragment shader:

Code:

#version 410 compatibility
in vec3 pass_Color;
out vec4 out_Color;
void main(void)
{
      out_Color = vec4(pass_Color, 1.0);
}

I have:
GL_VERSION: 4.1.0
GL_SHADING_LANGUAGE_VERSION: 4.10 NVIDIA via Cg compiler

What is wrong?
I attached fully function project made in QtCreator: Attachment 5643

I think that I will do the same in pure OpenGL without Qt. To look for mistakes. But if you can provide some answers or clues. That will be awesome.