diff --git a/TODO b/TODO
index ec258e6b..0f9a9b91 100644
--- a/TODO
+++ b/TODO
@@ -34,6 +34,26 @@
    
   test --crop in vipsthumbnail on portrait images cropped to landscape
 
+  alternative: if extract sees a seq image, it deliberately reads and discards
+  the N scanlines 
+
+  	could be very slow :-( 
+
+  the first vips_extract_area_gen() needs to somehow signal in
+  vips_region_prepare() that this is the first request
+
+  	how do we pass the signal down? not clear
+
+  run the first tile single-threaded
+
+  	so sinkdisc runs the first request, waits for it to come back, then
+	starts all the workers going
+
+	this is quite a good idea! we'd not slow down much, and there's a huge
+	amount of locking on the first tile anyway
+
+	now seq can support skipahead again
+
 
 
 
diff --git a/libvips/arithmetic/hough_circle.c b/libvips/arithmetic/hough_circle.c
index 8182fac7..b7a2d7bc 100644
--- a/libvips/arithmetic/hough_circle.c
+++ b/libvips/arithmetic/hough_circle.c
@@ -252,7 +252,7 @@ vips_hough_circle_class_init( VipsHoughClass *class )
 		G_STRUCT_OFFSET( VipsHoughCircle, min_radius ),
 		1, 100000, 10 );
 
-	VIPS_ARG_INT( class, "max_radius", 120, 
+	VIPS_ARG_INT( class, "max_radius", 121, 
 		_( "Max radius" ), 
 		_( "Largest radius to search for" ),
 		VIPS_ARGUMENT_OPTIONAL_INPUT,