Enlarge a gtable inside a ggroup; R gWidgets

Question

When I add a gtable inside a ggroup (using the RGtk2 guiToolkit) the gtable is very reduced, only 1 or 2 rows. Is there a solution to extend the gtable ?

Example :

library(gWidgets)
options("guiToolkit" = "RGtk2")
gwin <- gwindow()
group <- ggroup(horizontal = FALSE, spacing = 0, container = gwin)
gtable(iris, container = group)

I found nothing (maybe i looked bad...) in the gWidgets doc and examples.

It works using the tcltk guiToolkit :..

options("guiToolkit" = "tcltk")
gwin <- gwindow()
group <- ggroup(horizontal = FALSE, spacing = 0, container = gwin)
gtable(iris, container = group)

Thank you for any help