diff --git a/include/osgDB/InputStream b/include/osgDB/InputStream
index cf0999815..3ea247004 100644
--- a/include/osgDB/InputStream
+++ b/include/osgDB/InputStream
@@ -140,6 +140,9 @@ public:
     osg::Object* readObject( osg::Object* existingObj=0 );
     osg::Object* readObjectFields( const std::string& className, unsigned int id, osg::Object* existingObj=0);
 
+    void setByteSwap(int byteSwap) { _byteSwap = byteSwap; }
+    int getByteSwap() const { return _byteSwap; }
+    
     /// set an input iterator, used directly when not using InputStream with a traditional file releated stream.
     void setInputIterator( InputIterator* ii ) { _in = ii; }
 
diff --git a/include/osgDB/StreamOperator b/include/osgDB/StreamOperator
index 61c7f4daa..fdcb979a0 100644
--- a/include/osgDB/StreamOperator
+++ b/include/osgDB/StreamOperator
@@ -69,7 +69,7 @@ protected:
 class OSGDB_EXPORT InputIterator : public osg::Referenced
 {
 public:
-    InputIterator() : _in(0), _inputStream(0), _failed(false) {}
+    InputIterator() : _in(0), _inputStream(0), _byteSwap(0), _failed(false) {}
     virtual ~InputIterator() {}
     
     void setStream( std::istream* istream ) { _in = istream; }
@@ -79,7 +79,10 @@ public:
     void setInputStream( InputStream* inputStream) { _inputStream = inputStream; }
     InputStream* getInputStream() { return _inputStream; }
     const InputStream* getInputStream() const { return _inputStream; }
-    
+
+    void setByteSwap(int byteSwap) { _byteSwap = byteSwap; }
+    int getByteSwap() const { return _byteSwap; }
+
     void checkStream() const { if (_in->rdstate()&_in->failbit) _failed = true; }
     bool isFailed() const { return _failed; }
     
@@ -115,7 +118,8 @@ public:
 protected:
     std::istream*       _in;
     osgDB::InputStream* _inputStream;
-    mutable bool _failed;
+    int                 _byteSwap;
+    mutable bool        _failed;
 };
 
 }
diff --git a/src/osgDB/InputStream.cpp b/src/osgDB/InputStream.cpp
index 47ed5ba64..5bc63e4e6 100644
--- a/src/osgDB/InputStream.cpp
+++ b/src/osgDB/InputStream.cpp
@@ -683,6 +683,9 @@ InputStream::ReadType InputStream::start( InputIterator* inIterator )
 {
     _fields.clear();
     _fields.push_back( "Start" );
+
+    OSG_INFO<<"InputStream::start( InputIterator* inIterator ) calling setByteSwap("<<inIterator->getByteSwap()<<")"<<std::endl;
+    setByteSwap(inIterator->getByteSwap());
     
     ReadType type = READ_UNKNOWN;
     _in = inIterator;
diff --git a/src/osgPlugins/osg/BinaryStreamOperator.h b/src/osgPlugins/osg/BinaryStreamOperator.h
index 7cfa1ca09..ae0881de2 100644
--- a/src/osgPlugins/osg/BinaryStreamOperator.h
+++ b/src/osgPlugins/osg/BinaryStreamOperator.h
@@ -3,6 +3,14 @@
 
 #include <osgDB/StreamOperator>
 
+#if defined(_MSC_VER)
+typedef unsigned __int32 uint32_t;
+typedef __int32 int32_t;
+#else
+#include <stdint.h>
+#endif
+
+
 class BinaryOutputIterator : public osgDB::OutputIterator
 {
 public:
@@ -33,10 +41,18 @@ public:
     { _out->write( (char*)&i, osgDB::INT_SIZE ); }
     
     virtual void writeLong( long l )
-    { _out->write( (char*)&l, osgDB::LONG_SIZE ); }
-    
+    {
+        // On 64-bit systems a long may not be the same size as the file value
+        int32_t value=(int32_t)l;
+        _out->write( (char*)&value, osgDB::LONG_SIZE );
+    }
+
     virtual void writeULong( unsigned long l )
-    { _out->write( (char*)&l, osgDB::LONG_SIZE ); }
+    {
+        // On 64-bit systems a long may not be the same size as the file value
+        uint32_t value=(int32_t)l;
+        _out->write( (char*)&value, osgDB::LONG_SIZE );
+    }
     
     virtual void writeFloat( float f )
     { _out->write( (char*)&f, osgDB::FLOAT_SIZE ); }
@@ -73,9 +89,14 @@ public:
 class BinaryInputIterator : public osgDB::InputIterator
 {
 public:
-    BinaryInputIterator( std::istream* istream, bool byteSwap ) : _byteSwap(byteSwap) { _in = istream; }
-    virtual ~BinaryInputIterator() {}
+    BinaryInputIterator( std::istream* istream, int byteSwap )
+    {
+        _in = istream;
+        setByteSwap(byteSwap);
+    }
     
+    virtual ~BinaryInputIterator() {}
+
     virtual bool isBinary() const { return true; }
     
     virtual void readBool( bool& b )
@@ -120,14 +141,19 @@ public:
     
     virtual void readLong( long& l )
     {
-        _in->read( (char*)&l, osgDB::LONG_SIZE );
-        if ( _byteSwap ) osg::swapBytes( (char*)&l, osgDB::LONG_SIZE );
+        // On 64-bit systems a long may not be the same size as the file value
+        int32_t value;
+        _in->read( (char*)&value, osgDB::LONG_SIZE );
+        if ( _byteSwap ) osg::swapBytes( (char*)&value, osgDB::LONG_SIZE );
+        l = (long)value;
     }
     
     virtual void readULong( unsigned long& l )
     {
-        _in->read( (char*)&l, osgDB::LONG_SIZE );
-        if ( _byteSwap ) osg::swapBytes( (char*)&l, osgDB::LONG_SIZE );
+        uint32_t value;
+        _in->read( (char*)&value, osgDB::LONG_SIZE );
+        if ( _byteSwap ) osg::swapBytes( (char*)&value, osgDB::LONG_SIZE );
+        l = (unsigned long)value;
     }
     
     virtual void readFloat( float& f )
@@ -144,7 +170,8 @@ public:
     
     virtual void readString( std::string& s )
     {
-        int size = 0; readInt( size );
+        int size = 0;
+        readInt( size );
         if ( size>0 )
         {
             s.resize( size );
@@ -188,7 +215,6 @@ public:
     { readString( str ); }
     
 protected:
-    bool _byteSwap;
 };
 
 #endif
diff --git a/src/osgPlugins/osg/ReaderWriterOSG2.cpp b/src/osgPlugins/osg/ReaderWriterOSG2.cpp
index 990e31bba..d4865cedf 100644
--- a/src/osgPlugins/osg/ReaderWriterOSG2.cpp
+++ b/src/osgPlugins/osg/ReaderWriterOSG2.cpp
@@ -46,12 +46,12 @@ InputIterator* readInputIterator( std::istream& fin, const Options* options )
         if ( headerLow==OSG_HEADER_LOW && headerHigh==OSG_HEADER_HIGH )
         {
             OSG_INFO<<"Reading OpenSceneGraph binary file with the same endian as this computer."<<std::endl;
-            return new BinaryInputIterator(&fin, false); // endian the same so no byte swap required
+            return new BinaryInputIterator(&fin, 0); // endian the same so no byte swap required
         }
         else if ( headerLow==OSG_REVERSE(OSG_HEADER_LOW) && headerHigh==OSG_REVERSE(OSG_HEADER_HIGH) )
         {
             OSG_INFO<<"Reading OpenSceneGraph binary file with the different endian to this computer, doing byte swap."<<std::endl;
-            return new BinaryInputIterator(&fin, true); // endian different so byte swap required
+            return new BinaryInputIterator(&fin, 1); // endian different so byte swap required
         }
         
         fin.seekg( 0, std::ios::beg );