DocX/DocX.cs

             if(evenHeaderRef != null)
             {
                 XElement even = headers.even.Xml;
-                Uri target = mainPart.GetRelationship(evenHeaderRef).TargetUri;
+
+                Uri target = PackUriHelper.ResolvePartUri
+                (
+                    mainPart.Uri,
+                    mainPart.GetRelationship(evenHeaderRef).TargetUri
+                );
                 
                 using (TextWriter tw = new StreamWriter(package.GetPart(target).GetStream(FileMode.Create, FileAccess.Write)))
                 {
             if(oddHeaderRef != null)
             {
                 XElement odd = headers.odd.Xml;
-                Uri target = mainPart.GetRelationship(oddHeaderRef).TargetUri;
-               
+
+                Uri target = PackUriHelper.ResolvePartUri
+                (
+                    mainPart.Uri,
+                    mainPart.GetRelationship(oddHeaderRef).TargetUri
+                );
+
                 // Save header1
                 using (TextWriter tw = new StreamWriter(package.GetPart(target).GetStream(FileMode.Create, FileAccess.Write)))
                 {
             if(firstHeaderRef != null)
             {
                 XElement first = headers.first.Xml;
-                Uri target = mainPart.GetRelationship(firstHeaderRef).TargetUri;
+                Uri target = PackUriHelper.ResolvePartUri
+                (
+                    mainPart.Uri,
+                    mainPart.GetRelationship(firstHeaderRef).TargetUri
+                );
                
                 // Save header3
                 using (TextWriter tw = new StreamWriter(package.GetPart(target).GetStream(FileMode.Create, FileAccess.Write)))
             if(oddFooterRef != null)
             {
                 XElement odd = footers.odd.Xml;
-                Uri target = mainPart.GetRelationship(oddFooterRef).TargetUri;
+                Uri target = PackUriHelper.ResolvePartUri
+                (
+                    mainPart.Uri,
+                    mainPart.GetRelationship(oddFooterRef).TargetUri
+                );
              
                 // Save header1
                 using (TextWriter tw = new StreamWriter(package.GetPart(target).GetStream(FileMode.Create, FileAccess.Write)))
             if (evenFooterRef != null)
             {
                 XElement even = footers.even.Xml;
-                Uri target = mainPart.GetRelationship(evenFooterRef).TargetUri;
+                Uri target = PackUriHelper.ResolvePartUri
+                (
+                    mainPart.Uri,
+                    mainPart.GetRelationship(evenFooterRef).TargetUri
+                );
              
                 // Save header2
                 using (TextWriter tw = new StreamWriter(package.GetPart(target).GetStream(FileMode.Create, FileAccess.Write)))
             if (firstFooterRef != null)
             {         
                 XElement first = footers.first.Xml;
-                Uri target = mainPart.GetRelationship(firstFooterRef).TargetUri;
+                Uri target = PackUriHelper.ResolvePartUri
+                (
+                    mainPart.Uri,
+                    mainPart.GetRelationship(firstFooterRef).TargetUri
+                );
 
                 // Save header3
                 using (TextWriter tw = new StreamWriter(package.GetPart(target).GetStream(FileMode.Create, FileAccess.Write)))
             }
 
             // Close the document so that it can be saved.
-            Dispose();
+            package.Flush();
 
             #region Save this document back to a file or stream, that was specified by the user at save time.
             if (filename != null)
                 memoryStream.WriteTo(stream);
             }
             #endregion
-
-            // Re-open the document
-            package = Package.Open(memoryStream, FileMode.Open, FileAccess.ReadWrite);
         }
 
         /// <summary>
         }
 
         #endregion
-
-
     }
 }

DocX/Header.cs

                 return l;
             }
         }
+
+        public List<Image> Images
+        {
+            get
+            {
+                PackageRelationshipCollection imageRelationships = mainPart.GetRelationshipsByType("http://schemas.openxmlformats.org/officeDocument/2006/relationships/image");
+                if (imageRelationships.Count() > 0)
+                {
+                    return
+                    (
+                        from i in imageRelationships
+                        select new Image(Document, i)
+                    ).ToList();
+                }
+
+                return new List<Image>();
+            }
+        }
     }
 }

DocX/Properties/AssemblyInfo.cs

 // [assembly: AssemblyVersion("1.0.*")]
 [assembly: AssemblyVersion("1.0.0.10")]
 [assembly: AssemblyFileVersion("1.0.0.10")]
+
+[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("UnitTests")]

DocX/_Extensions.cs

 using System.Linq;
 using System.Text;
 using System.Drawing;
+using System.IO;
 
 namespace Novacode
 {