title: why does binding a GL_ELEMENT_ARRAY_BUFFER to 0 produce a memmove error?
body: <p>I had a bug that took me quite some time to fix. 
  I kept getting EXC_BAD_ACCESS and a reference to a memmove error without any further description until I commented the following line:  </p>
  
  <p>[self loadShaders];</p>
  
  <pre><code>glGenVertexArraysOES(1, &amp;_vao);
  glBindVertexArrayOES(_vao);
  
  // Vertex Buffer
  glGenBuffers(1, &amp;_vertexBuffer);
  glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);
  glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);
  
  glEnableVertexAttribArray(ATTRIB_VERTEX);
  glVertexAttribPointer(ATTRIB_VERTEX, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0);
  
  glEnableVertexAttribArray(ATTRIB_TEXTURE);
  glVertexAttribPointer(ATTRIB_TEXTURE, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*) (sizeof(float) * 7));
  
  // Index Buffer
  glGenBuffers(1, &amp;_indexBuffer);
  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _indexBuffer);
  glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW);
  
  glBindBuffer(GL_ARRAY_BUFFER,0);  
  
  ////////// COMMENTED THIS ONE //////////////
  //glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);//
  ////////////////////////////////////////////
  
  glBindVertexArrayOES(0);
  </code></pre>
  
  <p>I thought binding a buffer to 0 meant unbinding it, so I really cant understand how would that made my app crash.</p>
  
  <p>Thanks for the information! I just do not stay with this concern...</p>
  
  <p>My structures:</p>
  
  <pre><code>const Vertex Vertices[4] = {
      {{0.75, -1, 0}, {1, 0, 0, 1},     {0.125, 0.833496}},
      {{0.75, 1, 0}, {0, 1, 0, 1},      {0.125, 1}},
      {{-0.75, 1, 0}, {0, 0, 1, 1},     {0,     1}},
      {{-0.75, -1, 0}, {0, 0, 0, 1},    {0,     0.833496}},
  };
  
  const GLushort Indices[6] =
  {
      0, 1, 2,
      2, 3, 0
  };
  </code></pre>