Strange render error an AMD64 with 66.29

[locutus]

I observed a strange render behaviour in an application of the
company I am working for. I tracked down the Problem to a point
where the rendering fails. You will agree with me that the
following 4 code fragments should all work fine, but they don't.
All fragments together should render a box (part of a simple qt
sample program). The problem only occurs if you set the color
before glBegin and use glVertex3d to set the points.

// works
glBegin (GL_LINE_LOOP);
glColor3ub (200, 200, 200);
glVertex3d (1.0, 0.5, -0.4);
glVertex3d (1.0, -0.5, -0.4);
glVertex3d (-1.0, -0.5, -0.4);
glVertex3d (-1.0, 0.5, -0.4);
glEnd ();

// doesn't work
glColor3ub (200, 200, 200);
glBegin (GL_LINE_LOOP);
glVertex3d (1.0, 0.5, 0.4);
glVertex3d (1.0, -0.5, 0.4);
glVertex3d (-1.0, -0.5, 0.4);
glVertex3d (-1.0, 0.5, 0.4);
glEnd ();

// works
glColor3ub (200, 200, 200);
glBegin (GL_LINES);
glVertex3f (1.0, 0.5, -0.4);
glVertex3f (1.0, 0.5, 0.4);
glVertex3f (1.0, -0.5, -0.4);
glVertex3f (1.0, -0.5, 0.4);
glEnd();

// works
glBegin (GL_LINES);
glColor3ub (200, 200, 200);
glVertex3f (-1.0, -0.5, -0.4);
glVertex3f (-1.0, -0.5, 0.4);
glVertex3f (-1.0, 0.5, -0.4);
glVertex3f (-1.0, 0.5, 0.4);
glEnd();


Driver Version: 66.29
Distribution: based on SuSE 9.0
Video bios version: 04.28.20.33.01
Processor: Dual Opteron 246 (2 Ghz)
Graphic board: Quadro4 980 XGL
Motherboard: Tyan Thunder K8W (Revision 1.01)