diff --git a/src/osgPlugins/osga/OSGA_Archive.cpp b/src/osgPlugins/osga/OSGA_Archive.cpp
index 9fdaa4cba..84a47c848 100644
--- a/src/osgPlugins/osga/OSGA_Archive.cpp
+++ b/src/osgPlugins/osga/OSGA_Archive.cpp
@@ -234,8 +234,9 @@ bool OSGA_Archive::IndexBlock::getFileReferences(FileNamePositionMap& indexMap)
         
         std::string filename(ptr, ptr+filename_size);
         
-        // record this entry into the FileNamePositionMap
-        indexMap[filename] = PositionSizePair(position,size);
+        // record this entry into the FileNamePositionMap. 
+        // Requests for files will be in unix style even on Win32 so need unix style keys in map.
+        indexMap[osgDB::convertFileNameToUnixStyle(filename)] = PositionSizePair(position,size);
         
         ptr += filename_size;