The error is due to a nonconforming video card (i.e., one that reports
itself as supporting OpenGL 1.5, yet not exposing the required
functionality). If possible, please ask them to run "python -m
pyglet.info" and send in the results, so I can add in a permanent
workaround for those video cards.
It's also possibly a bug in pyglet, though this would likely have been
found by now.
You can work around the problem by setting
pyglet.options['graphics_vbo'] = False before importing any other
pyglet modules. This disables VBOs unconditionally, but this
shouldn't be a problem as your program doesn't look particularly
graphics intensive.
Cheers
Alex.