pixmap to pixbuf

Hi Espen,

I would like to get a pixbuf from my offscreen drawable.
I have written these bindings:

(defbinding colormap-get-system () colormap)

(defbinding pixbuf-get-from-drawable() (referenced pixbuf)
  (drawable drawable)
  (colormap colormap)
  (srx int)
  (sry int)
  (destx int)
  (desty int)
  (width int)
  (heigth int))

But when I call this function:

(defun pixmap-to-pixbuf ()
  (let ((map (gdk::pixmap-new 10 10 1))
     (cmap (gdk::colormap-get-system)))
    (gdk::pixbuf-get-from-drawable map cmap 0 0 0 0 10 10)
    ))

I have this error message:

Gdk: gdk_pixbuf_get_from_drawable: assertion `dest->colorspace == 
GDK_COLORSPACE_RGB' failed
   [Condition of type glib:critical-log-level]

In fact I don't know how to "specify" the destination pixbuf as the 
documentation says:
" If the specified destination pixbuf /dest/ is NULL, then this function 
will create an RGB pixbuf with 8 bits per channel and no alpha".

Have you any idea?

Thanx again.

Ephrem