diff --git a/DotCMIS/binding/atompub/atompub-linkcache.cs b/DotCMIS/binding/atompub/atompub-linkcache.cs
index e40688d..477d039 100644
--- a/DotCMIS/binding/atompub/atompub-linkcache.cs
+++ b/DotCMIS/binding/atompub/atompub-linkcache.cs
@@ -40,6 +40,7 @@
             KnownLinks.Add(AtomPubConstants.RelEditMedia);
             KnownLinks.Add(AtomPubConstants.RelPolicies);
             KnownLinks.Add(AtomPubConstants.RelVersionHistory);
+            KnownLinks.Add(AtomPubConstants.RelWorkingCopy);
             KnownLinks.Add(AtomPubConstants.LinkRelContent);
         }
 
diff --git a/DotCMIS/binding/atompub/atompub.cs b/DotCMIS/binding/atompub/atompub.cs
index bcf0a30..5bf1a00 100644
--- a/DotCMIS/binding/atompub/atompub.cs
+++ b/DotCMIS/binding/atompub/atompub.cs
@@ -2128,6 +2128,14 @@
                 ThrowLinkException(repositoryId, objectId, AtomPubConstants.RelSelf, AtomPubConstants.MediatypeEntry);
             }
 
+            // prefer working copy link if available
+            // (workaround for non-compliant repositories)
+            string wcLink = GetLink(repositoryId, objectId, AtomPubConstants.RelWorkingCopy, AtomPubConstants.MediatypeEntry);
+            if (wcLink != null)
+            {
+                link = wcLink;
+            }
+
             Delete(new UrlBuilder(link));
         }
 
@@ -2149,6 +2157,14 @@
                 ThrowLinkException(repositoryId, objectId, AtomPubConstants.RelSelf, AtomPubConstants.MediatypeEntry);
             }
 
+            // prefer working copy link if available
+            // (workaround for non-compliant repositories)
+            string wcLink = GetLink(repositoryId, objectId, AtomPubConstants.RelWorkingCopy, AtomPubConstants.MediatypeEntry);
+            if (wcLink != null)
+            {
+                link = wcLink;
+            }
+
             UrlBuilder url = new UrlBuilder(link);
             url.AddParameter(AtomPubConstants.ParamCheckinComment, checkinComment);
             url.AddParameter(AtomPubConstants.ParamMajor, major);
diff --git a/DotCMIS/data/data-impl.cs b/DotCMIS/data/data-impl.cs
index 68d9ef3..b0ff4a4 100644
--- a/DotCMIS/data/data-impl.cs
+++ b/DotCMIS/data/data-impl.cs
@@ -111,6 +111,7 @@
     {
         private List<IPropertyDefinition> propertyDefintionList = new List<IPropertyDefinition>();
         private Dictionary<string, IPropertyDefinition> propertyDefintionDict = new Dictionary<string, IPropertyDefinition>();
+        private string parentTypeId;
 
         public string Id { get; set; }
         public string LocalName { get; set; }
@@ -119,7 +120,11 @@
         public string QueryName { get; set; }
         public string Description { get; set; }
         public BaseTypeId BaseTypeId { get; set; }
-        public string ParentTypeId { get; set; }
+        public string ParentTypeId
+        {
+            get { return parentTypeId; }
+            set { parentTypeId = (value == null || value.Length == 0 ? null : value); }
+        }
         public bool? IsCreatable { get; set; }
         public bool? IsFileable { get; set; }
         public bool? IsQueryable { get; set; }