Disable quick green compressor, until I figure out what's the problem with it.

src/nvtt/CompressDXT.cpp

@@ -349,7 +349,8 @@ void nv::compressDXT5n(const Image * image, const OutputOptions::Private & outpu
 			}
 			
 			// Compress Y.
-			QuickCompress::compressDXT1G(rgba, &block.color);
+		//	QuickCompress::compressDXT1G(rgba, &block.color);
+			compressGreenBlock_BruteForce(rgba, &block.color);
 			
 			if (outputOptions.outputHandler != NULL) {
 				outputOptions.outputHandler->writeData(&block, sizeof(block));

src/nvtt/FastCompressDXT.cpp

@@ -904,10 +904,12 @@ void nv::compressGreenBlock_BruteForce(const ColorBlock & rgba, BlockDXT1 * bloc
 		maxg = max(maxg, green);
 	}
 
-	block->col0.u = 0;
-	block->col1.u = 0;
+	block->col0.r = 31;
+	block->col1.r = 31;
 	block->col0.g = maxg;
 	block->col1.g = ming;
+	block->col0.b = 0;
+	block->col1.b = 0;
 
 	if (maxg - ming > 4)
 	{