[GtkGLExt] button.cc example is slower than button.c or button.pl

[Mitchell Laks <mlaks post harvard edu>]

Hi,
I just  noticed that when I run the sample button programs that come with 
button.cc button.c button.pl

gtkglextmm
gtkglext
Gtk-GLext

the version written for gtkglextmm runs 1/2 as fast as the other two. Why is that?
The jumping doughnut (torus) rotates at 1/2 the speed, ie 15  not 30 revolutions per minute on 
my workstation with amd64 and nvidia 6600GT graphics card.

are all opengl applications that slow with gtkglextmm? i will try a nehe rotating texture square
next and compare it to the glut version.

Thank you,

mitchell