diff -Naur gnuplot-4.0.0/src/term.c gnuplot-4.0.0-new/src/term.c
--- gnuplot-4.0.0/src/term.c	2004-04-13 13:24:02.000000000 -0400
+++ gnuplot-4.0.0-new/src/term.c	2007-01-21 12:14:08.000000000 -0500
@@ -927,7 +927,7 @@
 	    ym = (int) (dy2 + backlen * sin( phi + beta ));
 	}
 #ifdef PM3D
-	if (curr_arrow_headfilled==2) {
+	if (curr_arrow_headfilled==2 && !clip_point(ex,ey)) {
 	    /* draw filled forward arrow head */
 	    filledhead[0].x = ex + xm;
 	    filledhead[0].y = ey + ym;
@@ -939,7 +939,8 @@
 	    filledhead[3].y = ey + y2;
 	    filledhead[4].x = ex + xm;
 	    filledhead[4].y = ey + ym;
-	    (*t->filled_polygon) (5, filledhead);
+	    if (t->filled_polygon)
+	      (*t->filled_polygon) (5, filledhead);
 	}
 #endif
 	/* draw outline of forward arrow head */
@@ -956,7 +957,7 @@
 	}
 	if (head == 2) { /* backward arrow head */
 #ifdef PM3D
-	    if (curr_arrow_headfilled==2) {
+	    if (curr_arrow_headfilled==2 && !clip_point(sx,sy)) {
 		/* draw filled backward arrow head */
 		filledhead[0].x = sx - xm;
 		filledhead[0].y = sy - ym;
@@ -968,7 +969,8 @@
 		filledhead[3].y = sy - y2;
 		filledhead[4].x = sx - xm;
 		filledhead[4].y = sy - ym;
-		(*t->filled_polygon) (5, filledhead);
+		if (t->filled_polygon)
+  		  (*t->filled_polygon) (5, filledhead);
 	    }
 #endif
 	    /* draw outline of backward arrow head */