I've just started digging through OpenGL and GLSL, and now stumbled on something I can't get my head around this one!? I've stepped back to loading a simple cube and using a simple shader on it, but the result is triangles drawn incorrectly and/or missing. The code I had working perfectly on meshes, but was attempting to move to using VAOs so none of the code for storing the vertices and indices has changed.

http://i.stack.imgur.com/RxxZ5.jpg

http://i.stack.imgur.com/zSU50.jpg

What I have for creating the VAO and buffers is this

//Create the Vertex array object
glGenVertexArrays(1, &vaoID);

// Finally create our vertex buffer objects
glGenBuffers(VBO_COUNT, mVBONames);

glBindVertexArray(vaoID);

    // Save vertex attributes into GPU
    glBindBuffer(GL_ARRAY_BUFFER, mVBONames[VERTEX_VBO]);

    // Copy data into the buffer object
    glBufferData(GL_ARRAY_BUFFER, lPolygonVertexCount*VERTEX_STRIDE*sizeof(GLfloat), lVertices, GL_STATIC_DRAW);

    glEnableVertexAttribArray(pos);
    glVertexAttribPointer(pos, 3, GL_FLOAT, GL_FALSE, VERTEX_STRIDE*sizeof(GLfloat),0);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mVBONames[INDEX_VBO]);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, lPolygonCount*sizeof(unsigned int), lIndices, GL_STATIC_DRAW);

glBindVertexArray(0);

And the code for drawing the mesh.

glBindVertexArray(vaoID);
glUseProgram(shader->programID);

GLsizei lOffset = mSubMeshes[pMaterialIndex]->IndexOffset*sizeof(unsigned int);
const GLsizei lElementCount = mSubMeshes[pMaterialIndex]->TriangleCount*TRIAGNLE_VERTEX_COUNT;
glDrawElements(GL_TRIANGLES, lElementCount, GL_UNSIGNED_SHORT, reinterpret_cast<const GLvoid*>(lOffset));

// All the points are indeed in the correct place!?
//glPointSize(10.0f);
//glDrawElements(GL_POINTS, lElementCount, GL_UNSIGNED_SHORT, 0);

glUseProgram(0);
glBindVertexArray(0);

Eyes have become bleary looking at this today so any thoughts or a fresh set of eyes would be greatly appreciated.