diff --git a/source/blender/blenkernel/intern/anim.c b/source/blender/blenkernel/intern/anim.c
index 13c5f45b107..bc0a89fd444 100644
--- a/source/blender/blenkernel/intern/anim.c
+++ b/source/blender/blenkernel/intern/anim.c
@@ -202,6 +202,7 @@ int interval_test(int min, int max, int p1, int cycl)
 	return p1;
 }
 
+/* warning, *vec needs FOUR items! */
 int where_on_path(Object *ob, float ctime, float *vec, float *dir)	/* returns OK */
 {
 	Curve *cu;
diff --git a/source/blender/blenkernel/intern/font.c b/source/blender/blenkernel/intern/font.c
index eb52689019a..a011431e16c 100644
--- a/source/blender/blenkernel/intern/font.c
+++ b/source/blender/blenkernel/intern/font.c
@@ -509,6 +509,7 @@ struct chartrans *text_to_curve(Object *ob, int mode)
 				CLAMP(ctime, 0.0, 1.0);
 
 				/* calc the right loc AND the right rot separately */
+				/* vec, tvec need 4 items */
 				where_on_path(cu->textoncurve, ctime, vec, tvec);
 				where_on_path(cu->textoncurve, ctime+dtime, tvec, rotvec);
 				
diff --git a/source/blender/blenkernel/intern/lattice.c b/source/blender/blenkernel/intern/lattice.c
index b5710565e61..5efbcd832b0 100644
--- a/source/blender/blenkernel/intern/lattice.c
+++ b/source/blender/blenkernel/intern/lattice.c
@@ -411,7 +411,7 @@ static void init_curve_deform(Object *par, Object *ob, CurveDeform *cd)
 
 }
 
-/* this makes sure we can extend for non-cyclic */
+/* this makes sure we can extend for non-cyclic. *vec needs 4 items! */
 static int where_on_path_deform(Object *ob, float ctime, float *vec, float *dir)	/* returns OK */
 {
 	Curve *cu= ob->data;
@@ -427,7 +427,8 @@ static int where_on_path_deform(Object *ob, float ctime, float *vec, float *dir)
 		ctime1= CLAMPIS(ctime, 0.0, 1.0);
 	}
 	else ctime1= ctime;
-
+	
+	/* vec needs 4 items */
 	if(where_on_path(ob, ctime1, vec, dir)) {
 		
 		if(cycl==0) {
@@ -456,7 +457,7 @@ static int where_on_path_deform(Object *ob, float ctime, float *vec, float *dir)
 static void calc_curve_deform(Object *par, float *co, short axis, CurveDeform *cd)
 {
 	Curve *cu= par->data;
-	float fac, loc[3], dir[3], *quat, mat[3][3], cent[3];
+	float fac, loc[4], dir[3], *quat, mat[3][3], cent[3];
 	short upflag, index;
 	
 	if(axis==OB_POSX || axis==OB_NEGX) {
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index da8fc63cc7e..0d2f216e24e 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -1009,6 +1009,7 @@ void ob_parcurve(Object *ob, Object *par, float mat[][4])
 		CLAMP(ctime, 0.0, 1.0);
 	}
 
+	/* vec: 4 items! */
  	if( where_on_path(par, ctime, vec, dir) ) {
 
 		if(cu->flag & CU_FOLLOW) {