diff --git a/ChangeLog b/ChangeLog
index 80f84de1..0ebb3a53 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,11 +3,17 @@
 - fix pngload with libpng >1.6.1
 - add vips_resize()
 
+21/8/14 started 7.40.7
+- fix matlab load
+- fix memleak in tilecache [Lovell]
+- fix memleak in VipsArray [Lovell]
+
 12/8/14 started 7.40.6
 - more doc fixes
 - fix similarity rotate+scale, thanks Topochicho
 - fix 16-bit PNG save, thanks John
 - fix dzsave date on Windows, thanks John
+- fix vipsthumbnail on many-core systems, thanks James
 
 25/7/14 started 7.40.5
 - fix a race in im_maxpos_avg()
diff --git a/configure.ac b/configure.ac
index 423dafb3..e375e4a6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -38,7 +38,7 @@ VIPS_VERSION_STRING=$VIPS_VERSION-`date`
 #   binary interface changes not backwards compatible?: reset age to 0
 
 LIBRARY_CURRENT=38
-LIBRARY_REVISION=4
+LIBRARY_REVISION=5
 LIBRARY_AGE=0
 
 # patched into include/vips/version.h
diff --git a/libvips/conversion/tilecache.c b/libvips/conversion/tilecache.c
index 69c88487..1634cdf1 100644
--- a/libvips/conversion/tilecache.c
+++ b/libvips/conversion/tilecache.c
@@ -29,6 +29,8 @@
  * 	- could deadlock if downstream raised an error (thanks Todd)
  * 25/4/13
  * 	- cache minimisation is optional, see "persistent" flag
+ * 26/8/14 Lovell
+ * 	- free the hash table in _dispose()
  */
 
 /*
@@ -156,6 +158,10 @@ vips_block_cache_dispose( GObject *gobject )
 	VIPS_FREEF( vips_g_mutex_free, cache->lock );
 	VIPS_FREEF( vips_g_cond_free, cache->new_tile );
 
+	if( cache->tiles )
+		g_assert( g_hash_table_size( cache->tiles ) == 0 );
+	VIPS_FREEF( g_hash_table_destroy, cache->tiles );
+
 	G_OBJECT_CLASS( vips_block_cache_parent_class )->dispose( gobject );
 }
 
@@ -941,7 +947,7 @@ vips_line_cache_build( VipsObject *object )
 
 		vips_get_tile_size( block_cache->in, 
 			&tile_width, &tile_height, &nlines );
-		block_cache->max_tiles = 3 * 
+		block_cache->max_tiles = 4 * 
 			(1 + nlines / block_cache->tile_height);
 
 		VIPS_DEBUG_MSG( "vips_line_cache_build: nlines = %d\n", 
diff --git a/libvips/foreign/matlab.c b/libvips/foreign/matlab.c
index fce0b5ee..a0f06a82 100644
--- a/libvips/foreign/matlab.c
+++ b/libvips/foreign/matlab.c
@@ -4,6 +4,9 @@
  *	- transpose on load, assemble planes into bands (thanks Mikhail)
  * 20/12/11
  * 	- reworked as some fns ready for new-style classes
+ * 21/8/14
+ * 	- swap width/height
+ * 	- set interpretation to rgb16 etc. 
  */
 
 /*
@@ -150,6 +153,28 @@ static int mat2vips_formats[][2] = {
 	{ MAT_C_DOUBLE, VIPS_FORMAT_DOUBLE }
 };
 
+/* Pick an interpretation.
+ */
+static VipsInterpretation 
+mat2vips_pick_interpretation( int bands, VipsBandFormat format )
+{
+	if( bands == 3 &&
+		vips_band_format_is8bit( format ) )
+		return( VIPS_INTERPRETATION_sRGB );
+	if( bands == 3 &&
+		(format == VIPS_FORMAT_USHORT || 
+		 format == VIPS_FORMAT_SHORT) )
+		return( VIPS_INTERPRETATION_RGB16 );
+	if( bands == 1 &&
+		(format == VIPS_FORMAT_USHORT || 
+		 format == VIPS_FORMAT_SHORT) )
+		return( VIPS_INTERPRETATION_GREY16 );
+	if( bands > 1 )
+		return( VIPS_INTERPRETATION_MULTIBAND ); 
+
+	return( VIPS_INTERPRETATION_MULTIBAND );
+}
+
 static int
 mat2vips_get_header( matvar_t *var, VipsImage *im )
 {
@@ -165,10 +190,10 @@ mat2vips_get_header( matvar_t *var, VipsImage *im )
 		bands = var->dims[2];
 
 	case 2:
-		height = var->dims[1];
+		width = var->dims[1];
 
 	case 1:
-		width = var->dims[0];
+		height = var->dims[0];
 		break;
 
 	default:
@@ -177,11 +202,6 @@ mat2vips_get_header( matvar_t *var, VipsImage *im )
 		return( -1 );
 	}
 
-	if( bands > 1 )
-		interpretation = VIPS_INTERPRETATION_MULTIBAND;
-	else
-		interpretation = VIPS_INTERPRETATION_B_W;
-
 	for( i = 0; i < VIPS_NUMBER( mat2vips_formats ); i++ )
 		if( mat2vips_formats[i][0] == var->class_type )
 			break;
@@ -191,6 +211,7 @@ mat2vips_get_header( matvar_t *var, VipsImage *im )
 		return( -1 );
 	}
 	format = mat2vips_formats[i][1];
+	interpretation = mat2vips_pick_interpretation( bands, format );
 
 	vips_image_init_fields( im,
 		 width, height, bands,
diff --git a/libvips/iofuncs/type.c b/libvips/iofuncs/type.c
index 8206dd71..897f55cc 100644
--- a/libvips/iofuncs/type.c
+++ b/libvips/iofuncs/type.c
@@ -334,6 +334,7 @@ vips_area_free_array_object( GObject **array, VipsArea *area )
 
 	for( i = 0; i < area->n; i++ ) 
 		VIPS_FREEF( g_object_unref, array[i] );
+	VIPS_FREE( array ); 
 
 	area->n = 0;
 }
diff --git a/tools/vipsthumbnail.c b/tools/vipsthumbnail.c
index d4a66e3f..cb250fc2 100644
--- a/tools/vipsthumbnail.c
+++ b/tools/vipsthumbnail.c
@@ -318,8 +318,10 @@ thumbnail_open( VipsObject *process, const char *filename )
 			"loading jpeg with factor %d pre-shrink", 
 			jpegshrink ); 
 
+		/* We can't use UNBUFERRED safely on very-many-core systems.
+		 */
 		if( !(im = vips_image_new_from_file( filename, 
-			"access", VIPS_ACCESS_SEQUENTIAL_UNBUFFERED,
+			"access", VIPS_ACCESS_SEQUENTIAL,
 			"shrink", jpegshrink,
 			NULL )) )
 			return( NULL );
@@ -328,7 +330,7 @@ thumbnail_open( VipsObject *process, const char *filename )
 		/* All other formats.
 		 */
 		if( !(im = vips_image_new_from_file( filename, 
-			"access", VIPS_ACCESS_SEQUENTIAL_UNBUFFERED,
+			"access", VIPS_ACCESS_SEQUENTIAL,
 			NULL )) )
 			return( NULL );
 	}