Please describe the problem:
When running sample base.c program from http://www.gtk.org/tutorial/c58.html
#include <gtk/gtk.h>
int main( int   argc, char *argv[] )
{
    GtkWidget *window;
    gtk_init (&argc, &argv);
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    gtk_widget_show  (window);
    gtk_main ();
    return 0;
}
under valgrind-3.1.0 with gtk-2.8.17 (Fedora Core 5 + updates) there are errors
detected.

Steps to reproduce:
1. gcc `pkg-config --cflags --libs gtk+-2.0` -g base.c
2. valgrind ./a.out

Actual results:
Valgrind detects the following error (two times):
==4256== Syscall param write(buf) points to uninitialised byte(s)
==4256==    at 0x1BA2D3: __write_nocancel (in /lib/libc-2.4.so)
==4256==    by 0x27D3EE: _X11TransWrite (in /usr/lib/libX11.so.6.2.0)
==4256==    by 0x283326: (within /usr/lib/libX11.so.6.2.0)
==4256==    by 0x28342A: _XReply (in /usr/lib/libX11.so.6.2.0)
==4256==    by 0x269281: XInternAtom (in /usr/lib/libX11.so.6.2.0)
==4256==    by 0x27CECB: XSetWMProperties (in /usr/lib/libX11.so.6.2.0)
==4256==    by 0x3944347: (within /usr/lib/libgdk-x11-2.0.so.0.800.17)
==4256==    by 0x3946AA5: gdk_window_new
            (in /usr/lib/libgdk-x11-2.0.so.0.800.17)
==4256==    by 0x392402C: gdk_display_open
            (in /usr/lib/libgdk-x11-2.0.so.0.800.17)
==4256==    by 0x3902AEE: gdk_display_open_default_libgtk_only
            (in /usr/lib/libgdk-x11-2.0.so.0.800.17)
==4256==    by 0x3AF8B9E: gtk_init_check
            (in /usr/lib/libgtk-x11-2.0.so.0.800.17)
==4256==    by 0x3AF8BD3: gtk_init (in /usr/lib/libgtk-x11-2.0.so.0.800.17)
==4256==  Address 0x406AA08 is 128 bytes inside a block of size 16,384 alloc'd
==4256==    at 0x40045EB: calloc (vg_replace_malloc.c:279)
==4256==    by 0x26E0D6: XOpenDisplay (in /usr/lib/libX11.so.6.2.0)
==4256==    by 0x3923EF1: gdk_display_open
            (in /usr/lib/libgdk-x11-2.0.so.0.800.17)
==4256==    by 0x3902AEE: gdk_display_open_default_libgtk_only
            (in /usr/lib/libgdk-x11-2.0.so.0.800.17)
==4256==    by 0x3AF8B9E: gtk_init_check
            (in /usr/lib/libgtk-x11-2.0.so.0.800.17)
==4256==    by 0x3AF8BD3: gtk_init (in /usr/lib/libgtk-x11-2.0.so.0.800.17)
==4256==    by 0x80485B3: main (base.c:8)


Expected results:
No errors detected by valgrind.

Does this happen every time?
Yes.

Other information: