GLU.Tessellator crashes

Hi,

I've just written some code which uses 'tessellate' from 
Graphics.Rendering.OpenGL.GLU.Tessellation and whilst it works exactly 
as expected on simple data sets, it gives a bus error on larger ones 
(not that large - e.g. 150 points).

This might be a bug in my OS's glu implementation, but I'm also inclined 
to suspect a bug in all the peeks and pokes HOpenGL uses to handle the 
data for the callbacks. I don't actually use the callback data (I've set 
all the data to (0 :: Int) only because there is no storable instance 
for ()).

Does anyone have a success story with this function? Has anyone used it 
successfully on larger polygons?

Jules