diff --git a/synaptics.c b/synaptics.c
index 63edebb..20a084e 100644
--- a/synaptics.c
+++ b/synaptics.c
@@ -400,6 +400,7 @@ #endif
     pars->tap_action[F2_TAP] = xf86SetIntOption(opts, "TapButton2",     2);
     pars->tap_action[F3_TAP] = xf86SetIntOption(opts, "TapButton3",     3);
     pars->circular_scrolling = xf86SetBoolOption(opts, "CircularScrolling", FALSE);
+    pars->adaptive_circle    = xf86SetBoolOption(opts, "AdaptiveCircle", TRUE);
     pars->circular_trigger   = xf86SetIntOption(opts, "CircScrollTrigger", 0);
     pars->circular_pad       = xf86SetBoolOption(opts, "CircularPad", FALSE);
     pars->palm_detect        = xf86SetBoolOption(opts, "PalmDetect", TRUE);
@@ -666,10 +667,7 @@ relative_coords(SynapticsPrivate *priv, 
 static double
 angle(SynapticsPrivate *priv, int x, int y)
 {
-    double xCenter = (priv->synpara->left_edge + priv->synpara->right_edge) / 2.0;
-    double yCenter = (priv->synpara->top_edge + priv->synpara->bottom_edge) / 2.0;
-
-    return xf86atan2(-(y - yCenter), x - xCenter);
+    return xf86atan2(-(y - priv->center_y), x - priv->center_x);
 }
 
 /* return angle difference */
@@ -684,6 +682,53 @@ diffa(double a1, double a2)
     return da;
 }
 
+/* reset center position to center of touchpad */
+static void
+reset_circ_scroll(SynapticsPrivate *priv, int x, int y)
+{
+    priv->center_x = (priv->synpara->left_edge + priv->synpara->right_edge) / 2.0;
+    priv->center_y = (priv->synpara->top_edge + priv->synpara->bottom_edge) / 2.0;
+    priv->scroll_x = x;
+    priv->scroll_y = y;
+    priv->scroll_a = -angle(priv, x, y);
+}
+
+/* calculate new center position */
+static void
+calculate_new_center(SynapticsPrivate *priv, double x, double y)
+{
+    double old_x = priv->scroll_x;
+    double old_y = priv->scroll_y;
+    double c_x = priv->center_x;
+    double c_y = priv->center_y;
+
+    double mid_x = (x + old_x)/2.0;
+    double mid_y = (y + old_y)/2.0;
+
+    double dx = x - old_x;
+    double dy = y - old_y;
+    double r = (mid_x - c_x)*(mid_x - c_x) + (mid_y - c_y)*(mid_y - c_y);
+
+    /* rotate <dx,dy> in the right direction to find new center */
+    double sign = (dx*(c_y - old_y) < dy*(c_x - old_x)) ? 1.0 : -1.0;
+    double scale;
+
+    /* only adjust center if we've moved a significant distance: *\
+    \*     100 units and about 6 degrees                         */
+    if (dx*dx + dy*dy < 10000.0 || dx*dx + dy*dy < 0.05 * r)
+        return;
+
+    /* detect if concavity changed, e.g. figure eight
+    sign *= (dx*(c_x - old_x) < dy*(old_y - c_y)) ? -1.0 : 1.0;
+    removed for now - causing small glitches and fairly useless anyway */
+
+    scale = sign * xf86sqrt(r/(dx*dx + dy*dy));
+    priv->center_x = mid_x + scale*dy;
+    priv->center_y = mid_y - scale*dx;
+    priv->scroll_x = x;
+    priv->scroll_y = y;
+}
+
 static edge_type
 circular_edge_detection(SynapticsPrivate *priv, int x, int y)
 {
@@ -1384,7 +1429,7 @@ HandleScrolling(SynapticsPrivate *priv, 
 		(para->circular_trigger == 8 && edge & LEFT_EDGE && edge & TOP_EDGE)) {
 		priv->circ_scroll_on = TRUE;
 		priv->circ_scroll_vert = TRUE;
-		priv->scroll_a = angle(priv, hw->x, hw->y);
+		reset_circ_scroll(priv, hw->x, hw->y);
 		DBG(7, ErrorF("circular scroll detected on edge\n"));
 	    }
 	}
@@ -1460,7 +1505,7 @@ HandleScrolling(SynapticsPrivate *priv, 
 	    priv->vert_scroll_edge_on = FALSE;
 	    priv->circ_scroll_on = TRUE;
 	    priv->circ_scroll_vert = TRUE;
-	    priv->scroll_a = angle(priv, hw->x, hw->y);
+	    reset_circ_scroll(priv, hw->x, hw->y);
 	    DBG(7, ErrorF("switching to circular scrolling\n"));
 	}
     }
@@ -1471,7 +1516,7 @@ HandleScrolling(SynapticsPrivate *priv, 
 	    priv->horiz_scroll_edge_on = FALSE;
 	    priv->circ_scroll_on = TRUE;
 	    priv->circ_scroll_vert = FALSE;
-	    priv->scroll_a = angle(priv, hw->x, hw->y);
+	    reset_circ_scroll(priv, hw->x, hw->y);
 	    DBG(7, ErrorF("switching to circular scrolling\n"));
 	}
     }
@@ -1513,26 +1558,29 @@ HandleScrolling(SynapticsPrivate *priv, 
     if (priv->circ_scroll_on) {
 	/* + = counter clockwise, - = clockwise */
 	double delta = para->scroll_dist_circ;
+
+	priv->scroll_a += angle(priv, hw->x, hw->y);
+        priv->scroll_a = diffa(0.0, priv->scroll_a);
+
 	if (delta >= 0.005) {
-	    while (diffa(priv->scroll_a, angle(priv, hw->x, hw->y)) > delta) {
+	    int dist = (int)(priv->scroll_a / delta);
+	    if (dist > 0) {
 		if (priv->circ_scroll_vert)
-		    sd->up++;
+		    sd->up += dist;
 		else
-		    sd->right++;
-		priv->scroll_a += delta;
-		if (priv->scroll_a > M_PI)
-		    priv->scroll_a -= 2 * M_PI;
-	    }
-	    while (diffa(priv->scroll_a, angle(priv, hw->x, hw->y)) < -delta) {
+		    sd->right += dist;
+	    } else {
 		if (priv->circ_scroll_vert)
-		    sd->down++;
+		    sd->down -= dist;
 		else
-		    sd->left++;
-		priv->scroll_a -= delta;
-		if (priv->scroll_a < -M_PI)
-		    priv->scroll_a += 2 * M_PI;
+		    sd->left -= dist;
 	    }
+	    priv->scroll_a -= dist*delta;
 	}
+
+	if (para->adaptive_circle)
+	    calculate_new_center(priv, hw->x, hw->y);
+        priv->scroll_a -= angle(priv, hw->x, hw->y);
     }
 
     if (priv->autoscroll_yspd) {
diff --git a/synaptics.h b/synaptics.h
index 12fe8dc..da760d7 100644
--- a/synaptics.h
+++ b/synaptics.h
@@ -87,6 +87,7 @@ typedef struct _SynapticsSHM
     Bool locked_drags;			    /* Enable locked drags */
     int tap_action[MAX_TAP];		    /* Button to report on tap events */
     Bool circular_scrolling;		    /* Enable circular scrolling */
+    Bool adaptive_circle;		    /* Try to guess circle location */
     double scroll_dist_circ;		    /* Scrolling angle radians */
     int circular_trigger;		    /* Trigger area for circular scrolling */
     Bool circular_pad;			    /* Edge has an oval or circular shape */
@@ -187,6 +188,8 @@ typedef struct _SynapticsPrivateRec
     int largest_valid_x;		/* Largest valid X coordinate seen so far */
     int scroll_y;			/* last y-scroll position */
     int scroll_x;			/* last x-scroll position */
+    int center_x;			/* center x position for circ scroll */
+    int center_y;			/* center y position for circ scroll */
     double scroll_a;			/* last angle-scroll position */
     int count_packet_finger;		/* packet counter with finger on the touchpad */
     int button_delay_millis;		/* button delay for 3rd button emulation */
diff --git a/synclient.c b/synclient.c
index 371611a..70a2932 100644
--- a/synclient.c
+++ b/synclient.c
@@ -92,6 +92,7 @@ static struct Parameter params[] = {
     DEFINE_PAR("TapButton2",           tap_action[F2_TAP],      PT_INT,    0, SYN_MAX_BUTTONS),
     DEFINE_PAR("TapButton3",           tap_action[F3_TAP],      PT_INT,    0, SYN_MAX_BUTTONS),
     DEFINE_PAR("CircularScrolling",    circular_scrolling,      PT_BOOL,   0, 1),
+    DEFINE_PAR("AdaptiveCircle",       adaptive_circle,         PT_BOOL,   0, 1),
     DEFINE_PAR("CircScrollDelta",      scroll_dist_circ,        PT_DOUBLE, .01, 3),
     DEFINE_PAR("CircScrollTrigger",    circular_trigger,        PT_INT,    0, 8),
     DEFINE_PAR("CircularPad",          circular_pad,            PT_BOOL,   0, 1),