diff --git a/src/nvtt/squish/alpha.cpp b/src/nvtt/squish/alpha.cpp
index 4242bb8..2d199a4 100644
--- a/src/nvtt/squish/alpha.cpp
+++ b/src/nvtt/squish/alpha.cpp
@@ -26,7 +26,7 @@
 #include "alpha.h"
 #include <algorithm>
 
-namespace squish {
+namespace nvsquish {
 
 static int FloatToInt( float a, int limit )
 {
@@ -323,4 +323,4 @@ void DecompressAlphaDxt5( u8* rgba, void const* block )
 		rgba[4*i + 3] = codes[indices[i]];
 }
 
-} // namespace squish
+} // namespace nvsquish
diff --git a/src/nvtt/squish/alpha.h b/src/nvtt/squish/alpha.h
index 2fb3baf..3b4ce02 100644
--- a/src/nvtt/squish/alpha.h
+++ b/src/nvtt/squish/alpha.h
@@ -28,7 +28,7 @@
 
 #include "squish.h"
 
-namespace squish {
+namespace nvsquish {
 
 void CompressAlphaDxt3( u8 const* rgba, void* block );
 void CompressAlphaDxt5( u8 const* rgba, void* block );
@@ -36,6 +36,6 @@ void CompressAlphaDxt5( u8 const* rgba, void* block );
 void DecompressAlphaDxt3( u8* rgba, void const* block );
 void DecompressAlphaDxt5( u8* rgba, void const* block );
 
-} // namespace squish
+} // namespace nvsquish
 
 #endif // ndef SQUISH_ALPHA_H
diff --git a/src/nvtt/squish/clusterfit.h b/src/nvtt/squish/clusterfit.h
index e115cd3..d4ee851 100644
--- a/src/nvtt/squish/clusterfit.h
+++ b/src/nvtt/squish/clusterfit.h
@@ -78,6 +78,6 @@ private:
 	int m_order[16];
 };
 
-} // namespace squish
+} // namespace nvsquish
 
 #endif // ndef SQUISH_CLUSTERFIT_H
diff --git a/src/nvtt/squish/colourblock.cpp b/src/nvtt/squish/colourblock.cpp
index 37e4b02..6bcb68c 100644
--- a/src/nvtt/squish/colourblock.cpp
+++ b/src/nvtt/squish/colourblock.cpp
@@ -53,7 +53,7 @@ static int FloatTo565( Vec3::Arg colour )
 	return ( r << 11 ) | ( g << 5 ) | b;
 }
 
-static void WriteColourBlock( int a, int b, u8* indices, void* block )
+void WriteColourBlock( int a, int b, u8* indices, void* block )
 {
 	// get the block as bytes
 	u8* bytes = ( u8* )block;
diff --git a/src/nvtt/squish/colourblock.h b/src/nvtt/squish/colourblock.h
index bb0c3b0..8ab0ace 100644
--- a/src/nvtt/squish/colourblock.h
+++ b/src/nvtt/squish/colourblock.h
@@ -31,6 +31,7 @@
 
 namespace nvsquish {
 
+void WriteColourBlock(int a, int b, u8* indices, void* block);
 void WriteColourBlock3( Vec3::Arg start, Vec3::Arg end, u8 const* indices, void* block );
 void WriteColourBlock4( Vec3::Arg start, Vec3::Arg end, u8 const* indices, void* block );
 //void WriteColourBlock3( Vec3::Arg start, Vec3::Arg end, uint indices, void* block );
diff --git a/src/nvtt/squish/rangefit.cpp b/src/nvtt/squish/rangefit.cpp
index 93c0a69..cda6e44 100644
--- a/src/nvtt/squish/rangefit.cpp
+++ b/src/nvtt/squish/rangefit.cpp
@@ -28,11 +28,12 @@
 #include "colourblock.h"
 #include <cfloat>
 
-namespace squish {
+namespace nvsquish {
 
-RangeFit::RangeFit( ColourSet const* colours, int flags ) 
-  : ColourFit( colours, flags )
+RangeFit::RangeFit( ColourSet const* colours, int flags )
 {
+	SetColourSet(colours, flags);
+
 	// initialise the metric
 	bool perceptual = ( ( m_flags & kColourMetricPerceptual ) != 0 );
 	if( perceptual )
@@ -49,7 +50,7 @@ RangeFit::RangeFit( ColourSet const* colours, int flags )
 	float const* weights = m_colours->GetWeights();
 	
 	// get the covariance matrix
-	Sym3x3 covariance = ComputeWeightedCovariance( count, values, weights );
+	Sym3x3 covariance = ComputeWeightedCovariance( count, values, weights, Vec3(1,1,1) );
 	
 	// compute the principle component
 	Vec3 principle = ComputePrincipleComponent( covariance );
@@ -199,4 +200,4 @@ void RangeFit::Compress4( void* block )
 	}
 }
 
-} // namespace squish
+} // namespace nvsquish
diff --git a/src/nvtt/squish/rangefit.h b/src/nvtt/squish/rangefit.h
index 7952019..6756b64 100644
--- a/src/nvtt/squish/rangefit.h
+++ b/src/nvtt/squish/rangefit.h
@@ -30,7 +30,7 @@
 #include "colourfit.h"
 #include "maths.h"
 
-namespace squish {
+namespace nvsquish {
 
 class ColourSet;
 
@@ -49,6 +49,6 @@ private:
 	float m_besterror;
 };
 
-} // squish
+} // namespace nvsquish
 
 #endif // ndef SQUISH_RANGEFIT_H
diff --git a/src/nvtt/squish/singlechannelfit.cpp b/src/nvtt/squish/singlechannelfit.cpp
index 2abc9a2..de88ac7 100644
--- a/src/nvtt/squish/singlechannelfit.cpp
+++ b/src/nvtt/squish/singlechannelfit.cpp
@@ -29,11 +29,12 @@
 #include "colourblock.h"
 #include <cfloat>
 
-namespace squish {
+namespace nvsquish {
 
-SingleChannelFit::SingleChannelFit( ColourSet const* colours, int const flags ) 
-  : ColourFit( colours, flags )
+SingleChannelFit::SingleChannelFit( ColourSet const* colours, int const flags )
 {
+	SetColourSet(colours, flags);
+
 	// cache some values
 	int const count = m_colours->GetCount();
 	Vec3 const* values = m_colours->GetPoints();
@@ -42,7 +43,7 @@ SingleChannelFit::SingleChannelFit( ColourSet const* colours, int const flags )
 	m_g_min = 63;
 	m_g_max = 0;
 	
-	for(uint i = 0; i < count; i++) {
+	for(int i = 0; i < count; i++) {
 		
 		int grey = int(values[i].Y() * 255.0f);	// @@ rounding?
 		grey = std::min(grey, 255);	// clamp to [0, 1)
@@ -141,4 +142,4 @@ void SingleChannelFit::Compress4( void* block )
 }
 
 
-} // namespace squish
+} // namespace nvsquish
diff --git a/src/nvtt/squish/singlechannelfit.h b/src/nvtt/squish/singlechannelfit.h
index 40de0a2..357ae8c 100644
--- a/src/nvtt/squish/singlechannelfit.h
+++ b/src/nvtt/squish/singlechannelfit.h
@@ -31,7 +31,7 @@
 #include "maths.h"
 #include "colourfit.h"
 
-namespace squish {
+namespace nvsquish {
 
 class SingleChannelFit : public ColourFit
 {
@@ -48,6 +48,6 @@ private:
 	int m_g_max;
 };
 
-} // namespace squish
+} // namespace nvsquish
 
 #endif // ndef SQUISH_SINGLECHANNELFIT_H
diff --git a/src/nvtt/squish/singlecolourfit.cpp b/src/nvtt/squish/singlecolourfit.cpp
index 4e1bb9c..3be544d 100644
--- a/src/nvtt/squish/singlecolourfit.cpp
+++ b/src/nvtt/squish/singlecolourfit.cpp
@@ -27,7 +27,7 @@
 #include "colourset.h"
 #include "colourblock.h"
 
-namespace squish {
+namespace nvsquish {
 
 struct SourceBlock
 {
@@ -59,8 +59,9 @@ static int FloatToInt( float a, int limit )
 }
 
 SingleColourFit::SingleColourFit( ColourSet const* colours, int flags )
-  : ColourFit( colours, flags )
 {
+	SetColourSet(colours, flags);
+
 	// grab the single colour
 	Vec3 const* values = m_colours->GetPoints();
 	m_colour[0] = ( u8 )FloatToInt( 255.0f*values->X(), 255 );
@@ -169,4 +170,4 @@ void SingleColourFit::ComputeEndPoints( int count, SingleColourLookup const* con
 	}
 }
 
-} // namespace squish
+} // namespace nvsquish
diff --git a/src/nvtt/squish/singlecolourfit.h b/src/nvtt/squish/singlecolourfit.h
index 3c4a1a3..eb75335 100644
--- a/src/nvtt/squish/singlecolourfit.h
+++ b/src/nvtt/squish/singlecolourfit.h
@@ -29,7 +29,7 @@
 #include <squish.h>
 #include "colourfit.h"
 
-namespace squish {
+namespace nvsquish {
 
 class ColourSet;
 struct SingleColourLookup;
@@ -53,6 +53,6 @@ private:
 	int m_besterror;
 };
 
-} // namespace squish
+} // namespace nvsquish
 
 #endif // ndef SQUISH_SINGLECOLOURFIT_H
diff --git a/src/nvtt/squish/squish.cpp b/src/nvtt/squish/squish.cpp
index 393ebf4..035d48a 100644
--- a/src/nvtt/squish/squish.cpp
+++ b/src/nvtt/squish/squish.cpp
@@ -32,7 +32,7 @@
 #include "alpha.h"
 #include "singlecolourfit.h"
 
-namespace squish {
+namespace nvsquish {
 
 static int FixFlags( int flags )
 {
@@ -85,7 +85,8 @@ void Compress( u8 const* rgba, void* block, int flags )
 	else
 	{
 		// default to a cluster fit
-		ClusterFit fit( &colours, flags );
+		ClusterFit fit;
+		fit.SetColourSet(&colours, flags);
 		fit.Compress( colourBlock );
 	}
 	
@@ -222,4 +223,4 @@ void DecompressImage( u8* rgba, int width, int height, void const* blocks, int f
 	}
 }
 
-} // namespace squish
+} // namespace nvsquish