Index: trunk/src/layer_ui.c
===================================================================
--- trunk/src/layer_ui.c	(revision 18338)
+++ trunk/src/layer_ui.c	(revision 18339)
@@ -114,7 +114,8 @@
 {
 	void **p;
 #warning TODO: switch to unique IDs
-	p = vtp0_get(&pcb_uilayers, ui_ly_id, 0);
+
+	p = vtp0_get(&pcb_uilayers, (ui_ly_id & (PCB_LYT_UI-1)), 0);
 	if (p == NULL)
 		return NULL;
 	return (pcb_layer_t *)(*p);
Index: trunk/src/layer_vis.c
===================================================================
--- trunk/src/layer_vis.c	(revision 18338)
+++ trunk/src/layer_vis.c	(revision 18339)
@@ -85,12 +85,12 @@
 
 
 	if (Layer & PCB_LYT_UI) {
+		pcb_layer_t *ly = pcb_uilayer_get(Layer);
+		if (ly == NULL)
+			return 0;
 		if (On < 0)
-			On = !pcb_uilayer.array[Layer].meta.real.vis;
-		Layer &= ~(PCB_LYT_UI | PCB_LYT_VIRTUAL);
-		if (Layer >= vtlayer_len(&pcb_uilayer))
-			return 0;
-		pcb_uilayer.array[Layer].meta.real.vis = On;
+			On = !ly->meta.real.vis;
+		ly->meta.real.vis = On;
 		changed = 1;
 		goto done;
 	}