Problem rendering on-the-fly objects

[yth]

Hi,

I'm experiencing strange effects when adding on-the-fly models to a scene using the vizshape module. When adding cylinders for example, the top and bottom of the cylinders are not closed, exposing various surfaces inside the cylinder and the reverse side of the cylinder can be seen through (see attachment). When creating a sphere, the result is a flat (2D) version of the sphere.

The described effects occur whenever such on-the-fly objects are added - e.g. when running the code from the tutorials. Other simulations run fine, such as the first tutorial showing the town square, plant models, avatars etc. Other OpenGL applications using 3D primitives seem to work fine, too. The problem occurs on a Lenovo Thinkpad R500 (which has a Mobile Intel 4 Express graphics card). Display drivers are up-to-date. My script runs fine on a second machine.

I'm not familiar with OpenGL, so I have no idea what could be causing these effects. What might be the problem here?

Thanks,
Yannick