Index: src/src/nvimage/ImageIO.cpp
===================================================================
--- src/src/nvimage/ImageIO.cpp	(revision 9895)
+++ src/src/nvimage/ImageIO.cpp	(working copy)
@@ -603,7 +603,7 @@
 {
 	nvDebugCheck(png_ptr != NULL);
 	
-	Stream * s = (Stream *)png_ptr->io_ptr;
+	Stream * s = (Stream *)png_get_io_ptr(png_ptr);
 	s->serialize(data, (int)length);
 	
 	if (s->isError()) {