Index: src/java/org/gnu/gtk/AboutDialog.java
===================================================================
RCS file: /cvs/gnome/libgtk-java/src/java/org/gnu/gtk/AboutDialog.java,v
retrieving revision 1.13
diff -u -r1.13 AboutDialog.java
--- src/java/org/gnu/gtk/AboutDialog.java	1 Oct 2005 15:21:59 -0000	1.13
+++ src/java/org/gnu/gtk/AboutDialog.java	10 Jan 2006 02:37:52 -0000
@@ -275,7 +275,8 @@
      * {@link Window#setDefaultIcon} will be used.
      */
     public void setLogo( Pixbuf val ) {
-        gtk_about_dialog_set_logo( getHandle(), val.getHandle() );
+    	Handle pixbufHandle = (val == null ? null : val.getHandle());
+        gtk_about_dialog_set_logo( getHandle(), pixbufHandle );
     }
     /**
      * Gets the pixbuf displayed as logo in the about dialog. 
Index: src/java/org/gnu/gtk/IconView.java
===================================================================
RCS file: /cvs/gnome/libgtk-java/src/java/org/gnu/gtk/IconView.java,v
retrieving revision 1.14
diff -u -r1.14 IconView.java
--- src/java/org/gnu/gtk/IconView.java	29 Oct 2005 10:34:17 -0000	1.14
+++ src/java/org/gnu/gtk/IconView.java	10 Jan 2006 02:37:56 -0000
@@ -67,7 +67,8 @@
      * @param model
      */
     public void setModel(TreeModel model) {
-        gtk_icon_view_set_model(getHandle(), model.getHandle());
+    	Handle modelHandle = (model == null ? null : model.getHandle());
+        gtk_icon_view_set_model(getHandle(), modelHandle);
     }
     
     /**
Index: src/java/org/gnu/gtk/TreeViewColumn.java
===================================================================
RCS file: /cvs/gnome/libgtk-java/src/java/org/gnu/gtk/TreeViewColumn.java,v
retrieving revision 1.46
diff -u -r1.46 TreeViewColumn.java
--- src/java/org/gnu/gtk/TreeViewColumn.java	14 Sep 2005 18:30:29 -0000	1.46
+++ src/java/org/gnu/gtk/TreeViewColumn.java	10 Jan 2006 02:38:21 -0000
@@ -237,7 +237,8 @@
 	 * @param widget : A child {@link Widget}, or null.
 	 */
 	public void setWidget(Widget widget) {
-		gtk_tree_view_column_set_widget(getHandle(), widget.getHandle());
+		Handle widgetHandle = (widget == null ? null : widget.getHandle());
+		gtk_tree_view_column_set_widget(getHandle(), widgetHandle);
 	}
 	
 	public Widget getWidget() {
Index: src/java/org/gnu/gtk/Widget.java
===================================================================
RCS file: /cvs/gnome/libgtk-java/src/java/org/gnu/gtk/Widget.java,v
retrieving revision 1.107
diff -u -r1.107 Widget.java
--- src/java/org/gnu/gtk/Widget.java	9 Jan 2006 21:09:04 -0000	1.107
+++ src/java/org/gnu/gtk/Widget.java	10 Jan 2006 02:38:25 -0000
@@ -462,8 +462,9 @@
 	 * @param y Y Position of the shape mask with respect to the window.
 	 */
 	public void shapeCombineMask(Bitmap shapeMask, int x, int y) {
+		Handle shapeMaskHandle = (shapeMask == null ? null : shapeMask.getHandle());
         checkState();
-		Widget.gtk_widget_shape_combine_mask(getHandle(), shapeMask.getHandle(), x, y);
+		Widget.gtk_widget_shape_combine_mask(getHandle(), shapeMaskHandle, x, y);
 	}
 
 	/**
