--- a/src/economy.cpp	Fri Jun 08 06:27:58 2007 +0000
+++ b/src/economy.cpp	Fri Jun 08 09:35:39 2007 +0000
@@ -1697,7 +1697,7 @@
 		InvalidateWindow(v->GetVehicleListWindowClass(), v->owner);
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 
-		st->MarkTilesDirty();
+		st->MarkTilesDirty(true);
 		v->MarkDirty();
 
 		if (result & 2) InvalidateWindow(WC_STATION_VIEW, last_visited);

--- a/src/station.cpp	Fri Jun 08 06:27:58 2007 +0000
+++ b/src/station.cpp	Fri Jun 08 09:35:39 2007 +0000
@@ -133,7 +133,7 @@
 	}
 }
 
-void Station::MarkTilesDirty() const
+void Station::MarkTilesDirty(bool cargo_change) const
 {
 	TileIndex tile = train_tile;
 	int w, h;
@@ -141,6 +141,15 @@
 	/* XXX No station is recorded as 0, not INVALID_TILE... */
 	if (tile == 0) return;
 
+	/* cargo_change is set if we're refreshing the tiles due to cargo moving
+	 * around. */
+	if (cargo_change) {
+		/* Don't waste time updating if there are no custom station graphics
+		 * that might change. Even if there are custom graphics, they might
+		 * not change. Unfortunately we have no way of telling. */
+		if (this->num_specs == 0) return;
+	}
+
 	for (h = 0; h < trainst_h; h++) {
 		for (w = 0; w < trainst_w; w++) {
 			if (TileBelongsToRailStation(tile)) {

--- a/src/station.h	Fri Jun 08 06:27:58 2007 +0000
+++ b/src/station.h	Fri Jun 08 09:35:39 2007 +0000
@@ -182,7 +182,7 @@
 
 	void AddFacility(byte new_facility_bit, TileIndex facil_xy);
 	void MarkDirty() const;
-	void MarkTilesDirty() const;
+	void MarkTilesDirty(bool cargo_change) const;
 	bool TileBelongsToRailStation(TileIndex tile) const;
 	uint GetPlatformLength(TileIndex tile, DiagDirection dir) const;
 	uint GetPlatformLength(TileIndex tile) const;

--- a/src/station_cmd.cpp	Fri Jun 08 06:27:58 2007 +0000
+++ b/src/station_cmd.cpp	Fri Jun 08 09:35:39 2007 +0000
@@ -978,7 +978,7 @@
 			tile_org += tile_delta ^ TileDiffXY(1, 1); // perpendicular to tile_delta
 		} while (--numtracks);
 
-		st->MarkTilesDirty();
+		st->MarkTilesDirty(false);
 		UpdateStationVirtCoordDirty(st);
 		UpdateStationAcceptance(st, false);
 		RebuildStationLists();
@@ -1105,7 +1105,7 @@
 			// now we need to make the "spanned" area of the railway station smaller if we deleted something at the edges.
 			// we also need to adjust train_tile.
 			MakeRailwayStationAreaSmaller(st);
-			st->MarkTilesDirty();
+			st->MarkTilesDirty(false);
 			UpdateStationSignCoord(st);
 
 			// if we deleted the whole station, delete the train facility.
@@ -2484,7 +2484,7 @@
 	st->goods[type].enroute_from = st->index;
 	st->goods[type].enroute_from_xy = st->xy;
 	InvalidateWindow(WC_STATION_VIEW, st->index);
-	st->MarkTilesDirty();
+	st->MarkTilesDirty(true);
 }
 
 /** Rename a station

--- a/src/vehicle.cpp	Fri Jun 08 06:27:58 2007 +0000
+++ b/src/vehicle.cpp	Fri Jun 08 09:35:39 2007 +0000
@@ -2964,7 +2964,7 @@
 	InvalidateWindow(WC_VEHICLE_DETAILS, this->index);
 	InvalidateWindow(WC_STATION_VIEW, this->last_station_visited);
 
-	GetStation(this->last_station_visited)->MarkTilesDirty();
+	GetStation(this->last_station_visited)->MarkTilesDirty(true);
 	this->MarkDirty();
 }