GL_DEPTH_TEST causes rendering problems with trian

I’ve got my OpenGL ES code working and rendering great and very fast, however I’m now having a weird issue related to depth tests. What happens is any vertice whose Z value is not exactly 0.0f causes that entire portion of the object to not get drawn. So if the Z values of the 4 points are 0.1f,0.0f,0.0f,0.0f, then the entire top-left triangle will not be drawn at all (which makes sense - if there was something occluding it, which there isn’t as I’m testing this with only one object in the scene).

Here is the code I’m using:

//PUAP -Mat use GL_MODULATE to tint, GL_REPLACE for texture only
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );

// Clear our color and depth buffers  
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);  
  
// Array of render vertices   
GLfloat renderObjVects[] =   
{  
    -1.0f, -1.0f, 0.1f,  // Bottom Left  
    1.0f, -1.0f, 0.0f,  // Bottom Right   
    -1.0f, 1.0f, 0.0f,  // Top Left  
    1.0f, 1.0f, 0.0f   // Top Right  
};    
  
// Array of texture coordinates   
GLfloat texCoords[] =   
{  
    1.0f, 0.0f,  
    0.0f, 0.0f,  
    1.0f, 1.0f,  
    0.0f, 1.0f   
};    
          
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);  
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);     
  
// Enable Properties  
glEnable(GL_TEXTURE_2D);  
glEnable(GL_BLEND);  
glEnable(GL_LIGHTING);  
glEnable(GL_LIGHT0);      
  
// Set our blend types  
glBlendFunc(GL_ONE, GL_SRC_COLOR);  
  
// Enable depth checking so objects can layer  
glEnable(GL_DEPTH_TEST);      
glDepthFunc(GL_LEQUAL);  
glClearDepthf(1.0f);  
glClear(GL_DEPTH_BUFFER_BIT);     
  
// Enable our pointers.  
glVertexPointer(3, GL_FLOAT, 0, renderObjVects);  
glTexCoordPointer(2, GL_FLOAT, 0, texCoords);     
  
// Set our Projection Mode  
glMatrixMode(GL_MODELVIEW);  
  
// Set the shading model  
glShadeModel(GL_SMOOTH);  


// Clear things out  
glColor4f(0.0, 0.0, 0.0, 0.0);  
glClear(GL_COLOR_BUFFER_BIT);                     
              
glEnableClientState(GL_VERTEX_ARRAY);  
glEnableClientState(GL_TEXTURE_COORD_ARRAY);  
                              
glLoadIdentity();  
          
// Bind this imagemap for use  
glBindTexture( GL_TEXTURE_2D, thisData.mpPageTextureHandle->getGLName() );  
              
// Now... let's draw!                 
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);  

Here is a screenshot of the problem in action using the above code: Picasa Image Link of a Banana