diff -ur openbox-3.3-rc2/openbox/prop.c openbox-3.3-rc2.bak/openbox/prop.c
--- openbox-3.3-rc2/openbox/prop.c	2004-03-21 02:03:00.000000000 +0100
+++ openbox-3.3-rc2.bak/openbox/prop.c	2005-10-12 13:45:58.000000000 +0200
@@ -206,7 +206,7 @@
                     data[i] = xdata[i];
                     break;
                 case 16:
-                    ((guint16*)data)[i] = ((guint16*)xdata)[i];
+                    ((guint16*)data)[i] = ((gushort*)xdata)[i];
                     break;
                 case 32:
                     ((guint32*)data)[i] = ((gulong*)xdata)[i];
@@ -245,7 +245,7 @@
                     (*data)[i] = xdata[i];
                     break;
                 case 16:
-                    ((guint16*)*data)[i] = ((guint16*)xdata)[i];
+                    ((guint16*)*data)[i] = ((gushort*)xdata)[i];
                     break;
                 case 32:
                     ((guint32*)*data)[i] = ((gulong*)xdata)[i];
@@ -385,15 +385,27 @@
 
 void prop_set32(Window win, Atom prop, Atom type, guint32 val)
 {
+    gulong lval = val;
     XChangeProperty(ob_display, win, prop, type, 32, PropModeReplace,
-                    (guchar*)&val, 1);
+                    (guchar*)&lval, 1);
 }
 
 void prop_set_array32(Window win, Atom prop, Atom type, guint32 *val,
                       guint num)
 {
+    gulong *gval;
+    int i;
+
+    gval = g_new(gulong, num);
+
+    for(i = 0; i < num; i++) {
+        gval[i] = val[i];
+    }
+
     XChangeProperty(ob_display, win, prop, type, 32, PropModeReplace,
-                    (guchar*)val, num);
+                    (guchar*)gval, num);
+
+    g_free(gval);
 }
 
 void prop_set_string_utf8(Window win, Atom prop, gchar *val)