GlGtk + Thread?

Hello,

I'm using lablgtk installed from godi on a linux box.

I tried to modify the "simple.ml" example (GL sub-directory) in order to
have thread enabled:
- I replaced Main.main by GtkThread.main
- and ran the example with: lablgtk2 -thread gtkThread.cmo simple.ml

Unfortunately, this did not work. No idea why. There is the message
(from the C part?):

GlGtk-WARNING **: could not make current

Any idea?

My initial goal was to try to make a gtk application, with a separated
thread re-drawing the GlGtk area.

Thanks in advance

Matt