Index: trunk/src_plugins/lib_gtk_common/wt_layersel.c
===================================================================
--- trunk/src_plugins/lib_gtk_common/wt_layersel.c	(revision 8657)
+++ trunk/src_plugins/lib_gtk_common/wt_layersel.c	(revision 8658)
@@ -535,14 +535,15 @@
 {
 	pcb_layergrp_id_t gid;
 
-	for(gid = 0; gid < pcb_max_group(PCB); gid++) {
+	for(gid = 0; gid < pcb_max_group(PCB); gid++)
 		free(ls->grp[gid].layer);
-		ls->grp[gid].layer = NULL;
-	}
 
 	free(ls->lsg_virt.layer);
-	ls->lsg_virt.layer = NULL;
 
+	memset(&ls->grp, 0, sizeof(ls->grp));
+	memset(&ls->lsg_virt, 0, sizeof(ls->lsg_virt));
+	memset(&ls->grp_virt, 0, sizeof(ls->grp_virt));
+
 	gtk_widget_destroy(ls->grp_box);
 	ls->grp_box = gtkc_vbox_new(FALSE, 0);
 	gtk_box_pack_start(GTK_BOX(ls->grp_box_outer), ls->grp_box, FALSE, FALSE, 0);