diff --git a/TODO b/TODO
index 73b56a9d..98919efc 100644
--- a/TODO
+++ b/TODO
@@ -4,37 +4,6 @@
 
 	trim this down!
 
-- seq is disabled in colour.c
-
-
-
-- try:
-
-	$ valgrind --db-attach=yes vips sRGB2XYZ kylie110.jpg x2.v --vips-cache-trace --vips-concurrency=1 --vips-progress
-
-  get:
-
-	==22629== Thread 4:
-	==22629== Conditional jump or move depends on uninitialised value(s)
-	==22629==    at 0x4EDA287: vips_col_sRGB2XYZ (LabQ2sRGB.c:259)
-	==22629==    by 0x4EDB1DC: vips_sRGB2XYZ_line (sRGB2XYZ.c:78)
-
-
-  the .jpg is read to a mem buffer, we then process from that
-
-  the mem buffer is created OK and we don't get unint errors if we read from
-  there during create
-
-  the vips_sRGB2XYZ_line() is called with p pointing to the start of the mem
-  buffer and triggers the uninit
-
-  therefore something during the rewind must be causing uninit to be set
-
-
-
-
-
-
 
 - add mono as a colourspace? also rad?
 
diff --git a/libvips/colour/colour.c b/libvips/colour/colour.c
index c1543462..ae855c12 100644
--- a/libvips/colour/colour.c
+++ b/libvips/colour/colour.c
@@ -69,20 +69,6 @@ vips_colour_gen( VipsRegion *or,
 		if( vips_region_prepare( ir[i], r ) ) 
 			return( -1 );
 
-	int x;
-	int sum;
-
-	printf( "vips_colour_gen: testing mem buffer #5 %p for uninit\n",
-		VIPS_REGION_ADDR( ir[0], r->left, r->top ) );
-	sum = 0;
-	for( y = 0; y < r->height; y++ )
-		for( x = 0; x < r->width; x++ )
-			sum += 
-			VIPS_REGION_ADDR( ir[0], x + r->left, y + r->top )[0] +
-			VIPS_REGION_ADDR( ir[0], x + r->left, y + r->top )[1] +
-			VIPS_REGION_ADDR( ir[0], x + r->left, y + r->top )[2];
-	printf( "sum = %d\n", sum );
-
 	for( y = 0; y < r->height; y++ ) {
 		for( i = 0; ir[i]; i++ )
 			p[i] = VIPS_REGION_ADDR( ir[i], r->left, r->top + y );
@@ -180,7 +166,7 @@ vips_colour_class_init( VipsColourClass *class )
 	vobject_class->description = _( "colour operations" );
 	vobject_class->build = vips_colour_build;
 
-	//operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
+	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
 
 	VIPS_ARG_IMAGE( class, "out", 100, 
 		_( "Output" ), 
diff --git a/libvips/colour/sRGB2XYZ.c b/libvips/colour/sRGB2XYZ.c
index 8e5a8a2c..a00fac73 100644
--- a/libvips/colour/sRGB2XYZ.c
+++ b/libvips/colour/sRGB2XYZ.c
@@ -64,18 +64,6 @@ vips_sRGB2XYZ_line( VipsColour *colour, VipsPel *out, VipsPel **in, int width )
 
 	int i;
 
-	printf( "vips_sRGB2XYZ_line: out = %p, in = %p\n",
-		out, p );
-
-	int sum;
-
-	printf( "vips_sRGB2XYZ_line: testing mem buffer #6 %p for uninit\n",
-		p ); 
-	sum = 0;
-	for( i = 0; i < width; i++ )
-		sum += p[0] + p[1] + p[2];
-	printf( "sum = %d\n", sum );
-
 	for( i = 0; i < width; i++ ) {
 		int r = p[0];
 		int g = p[1];
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index 7b91b3b2..c23e0595 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -33,8 +33,8 @@
  */
 
 /*
- */
 #define DEBUG
+ */
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -791,19 +791,6 @@ vips_foreign_load_start( VipsImage *out, void *a, void *b )
 			load->real, NULL );
 	}
 
-        if( load->real->dtype == VIPS_IMAGE_SETBUF ) { 
-		int x, y;
-		int sum;
-
-		printf( "testing mem buffer #3 %p for uninit\n",
-			VIPS_IMAGE_ADDR( load->real, 0, 0 ) );
-		sum = 0;
-		for( y = 0; y < load->real->Ysize; y++ )
-			for( x = 0; x < load->real->Xsize; x++ )
-				sum += *VIPS_IMAGE_ADDR( load->real, x, y );
-		printf( "sum = %d\n", sum );
-	}
-
 	return( vips_region_new( load->real ) );
 }
 
@@ -827,22 +814,6 @@ vips_foreign_load_generate( VipsRegion *or,
         if( vips_region_region( or, ir, r, r->left, r->top ) )
                 return( -1 );
 
-{ 
-	int x, y;
-	int sum;
-
-	printf( "vips_foreign_load_generate: testing mem buffer #4 %p for uninit\n",
-		VIPS_REGION_ADDR( or, r->left, r->top ) );
-	sum = 0;
-	for( y = 0; y < r->height; y++ )
-		for( x = 0; x < r->width; x++ )
-			sum += 
-			VIPS_REGION_ADDR( or, x + r->left, y + r->top )[0] +
-			VIPS_REGION_ADDR( or, x + r->left, y + r->top )[1] +
-			VIPS_REGION_ADDR( or, x + r->left, y + r->top )[2];
-	printf( "sum = %d\n", sum );
-}
-
         return( 0 );
 }
 
diff --git a/libvips/iofuncs/generate.c b/libvips/iofuncs/generate.c
index 2a8fb7bc..0e83dadb 100644
--- a/libvips/iofuncs/generate.c
+++ b/libvips/iofuncs/generate.c
@@ -700,24 +700,9 @@ vips_image_generate( VipsImage *image,
                 if( image->dtype == VIPS_IMAGE_OPENOUT ) 
 			res = vips_sink_disc( image,
 				(VipsRegionWrite) write_vips, NULL );
-                else {
-			int x, y;
-			int sum;
-
+                else 
                         res = vips_sink_memory( image );
 
-			printf( "testing mem buffer %p for uninit\n",
-				VIPS_IMAGE_ADDR( image, 0, 0 ) );
-			sum = 0;
-			for( y = 1; y < image->Ysize; y++ )
-				for( x = 0; x < image->Xsize; x++ ) {
-					printf( "x = %d\n", 
-					*VIPS_IMAGE_ADDR( image, x, y ) );
-					sum += *VIPS_IMAGE_ADDR( image, x, y );
-				}
-			printf( "sum = %d\n", sum );
-		}
-
                 /* Error?
                  */
                 if( res )
@@ -738,18 +723,5 @@ vips_image_generate( VipsImage *image,
 	if( vips_image_written( image ) )
 		return( -1 );
 
-        if( image->dtype == VIPS_IMAGE_SETBUF ) { 
-		int x, y;
-		int sum;
-
-		printf( "testing mem buffer #2 %p for uninit\n",
-			VIPS_IMAGE_ADDR( image, 0, 0 ) );
-		sum = 0;
-		for( y = 0; y < image->Ysize; y++ )
-			for( x = 0; x < image->Xsize; x++ )
-				sum += *VIPS_IMAGE_ADDR( image, x, y );
-		printf( "sum = %d\n", sum );
-	}
-
         return( 0 );
 }
diff --git a/libvips/iofuncs/image.c b/libvips/iofuncs/image.c
index bbe065ad..def5d7f1 100644
--- a/libvips/iofuncs/image.c
+++ b/libvips/iofuncs/image.c
@@ -31,8 +31,8 @@
  */
 
 /*
- */
 #define VIPS_DEBUG
+ */
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -1896,9 +1896,6 @@ vips_image_write_prepare( VipsImage *image )
 				VIPS_IMAGE_SIZEOF_IMAGE( image ))) ) 
 			return( -1 );
 
-		printf( "vips_image_write_prepare: memory image at %p\n", 
-				image->data );
-
 		break;
 
 	case VIPS_IMAGE_OPENOUT:
diff --git a/libvips/iofuncs/sinkmemory.c b/libvips/iofuncs/sinkmemory.c
index 91c02229..e794aa4b 100644
--- a/libvips/iofuncs/sinkmemory.c
+++ b/libvips/iofuncs/sinkmemory.c
@@ -324,8 +324,6 @@ vips_sink_memory( VipsImage *image )
 	SinkMemory memory;
 	int result;
 
-	printf( "vips_sink_memory: writing to %p\n", image->data );
-
 	if( sink_memory_init( &memory, image ) )
 		return( -1 );
 
@@ -345,7 +343,6 @@ vips_sink_memory( VipsImage *image )
 
 	sink_memory_free( &memory );
 
-	printf( "vips_sink_memory: done\n" );
 	VIPS_DEBUG_MSG( "vips_sink_memory: done\n" );
 
 	return( result );