glSelection help... please?

I am at the end of my rope with doing selection under gl. Right now I am using
the basic gl seleciton technique as follows:

glGetIntegerv(GL_VIEWPORT, viewport);

glSelectBuffer(BUFFER_LENGTH, selectBuff);


// set up the name stack



gluPickMatrix((GLdouble)xPos1, (GLdouble)viewport[3] - yPos1, (GLdouble) 2, (GLdouble) 2, viewport);

// set either orthographic or perspective
// projection
m_activeCamera->setProjection( );

// translate to camera’s position in scene
m_activeCamera->apply( );

// Draw the scene - calling glLoadName before each object drawn.
m_scene->draw( GL_SELECT );

glFlush ( );

// Collect the hits
hits = glRenderMode(GL_RENDER);
… process hits …

The problem is that I am getting inconsistant
results. Sometimes I’ll select nothing and
get all but one of my objects back as hits.

One specific case which is mind boggiling is
where I only have 2 quads in a scene. I click
the bottom one and it returns the correct
GLuint as the picked name in the selection
buffer. I select the top one and i get a
return of 1 hit with no name:
hits = 1;
selectBuff 0x0012f854
[0] 0 - number of names - wtf?
[1] 0 - min z
[2] 0 - max z
[3] 3435973836

I have seen the same results on a G400 and
a geForce 256 under win2k.

Any Ideas? Anyone?


Looks very similar to the SELECT.C from the redbook samples, except for the name stack bottom element initialisation (glPushName(-1)).
Does this redbook sample work for you?
If yes, ask yourself what you have done differently.