Kevin Raymond reports the same problem with devg-gma9xx driver here:
http://community.qnx.com/sf/discussion/do/listPosts/projects.bsp/discussion.bsp.topc6952

I'm able to reproduce this problem on devg-extreme2, but test application will be in binary form, since it using a lot 
of dependencies to software which is under development.

The same binaries work fine using software GLES implementation. Under devg-extreme2:

sphere - uses QNX's native egl interface. All points on sphere are drawed correctly.
sdl_sphere - uses SDL which initializes all GLES stuff, like it done in "sphere" test, applications are very similar to 
each other, even the same. But the sphere located in the middle-bottom has been drawn incorrectly, when sdl_sphere 
renders sphere of points.

Take a look into it.