diff --git a/src/QABugs/QABugs_20.cxx b/src/QABugs/QABugs_20.cxx
index 7a5e33bee5..80f90678cb 100644
--- a/src/QABugs/QABugs_20.cxx
+++ b/src/QABugs/QABugs_20.cxx
@@ -2802,6 +2802,38 @@ static Standard_Integer OCC29430(Draw_Interpretor& theDI,
   return 0;
 }
 
+#include <STEPCAFControl_Reader.hxx>
+
+//=======================================================================
+//function : OCC29531
+//purpose  : 
+//=======================================================================
+static Standard_Integer OCC29531(Draw_Interpretor&, Standard_Integer, const char** theArgV)
+{
+  Handle(TDocStd_Application) anApp = DDocStd::GetApplication();
+  Handle(TDocStd_Document) aDoc;
+  anApp->NewDocument("BinOcaf", aDoc);
+  aDoc->SetUndoLimit(1);
+
+  STEPCAFControl_Reader Reader;
+  Reader.ReadFile(theArgV[1]);
+  Reader.Transfer(aDoc);
+  TDF_Label aShL, aDL;
+  TDF_Tool::Label(aDoc->GetData(), "0:1:1:2:672", aShL);
+  TDF_Tool::Label(aDoc->GetData(), "0:1:4:10", aDL);
+
+  aDoc->OpenCommand();
+
+  Handle(XCAFDoc_DimTolTool) aDimTolTool = XCAFDoc_DocumentTool::DimTolTool(aDoc->Main());
+  aDimTolTool->SetDimension(aShL, aDL);
+
+  aDoc->CommitCommand();
+
+  aDoc->Undo();
+  aDoc->Redo();
+  return 0;
+}
+
 void QABugs::Commands_20(Draw_Interpretor& theCommands) {
   const char *group = "QABugs";
 
@@ -2835,6 +2867,7 @@ void QABugs::Commands_20(Draw_Interpretor& theCommands) {
   theCommands.Add("OCC29430", "OCC29430 <result wire> "
                               "<result first point> <result last point>",
                               __FILE__, OCC29430, group);
+  theCommands.Add("OCC29531", "OCC29531 <step file name>", __FILE__, OCC29531, group);
 
   return;
 }
diff --git a/src/TDF/TDF_Data.cxx b/src/TDF/TDF_Data.cxx
index 96cdd85811..a6d8df8ac1 100644
--- a/src/TDF/TDF_Data.cxx
+++ b/src/TDF/TDF_Data.cxx
@@ -375,42 +375,25 @@ Standard_Boolean TDF_Data::IsApplicable
 //=======================================================================
 void TDF_Data::FixOrder(const Handle(TDF_Delta)& theDelta)
 {
+  // make all OnRemoval (which will cause addition of the attribute) are in the end
+  // to do not put two attributes with the same GUID at one label during undo/redo
+  TDF_AttributeDeltaList anOrderedList;
+
   const TDF_AttributeDeltaList& attList = theDelta->AttributeDeltas();
-  Handle(TDF_AttributeDelta) attDelta;
-  Handle(TDF_Attribute) att;
-  Standard_Integer i, indx1(0), indx2(0);
-  Standard_GUID aGuid;
-  TDF_ListIteratorOfAttributeDeltaList itr(attList) ;
-  for (i=1; itr.More(); itr.Next(), i++) {
-    attDelta = itr.Value();
-    if(indx1) {
-      att = attDelta->Attribute();
-      if((att->ID() == aGuid) && (attDelta->IsKind(STANDARD_TYPE(TDF_DeltaOnAddition)))) {
-        indx2 = i;
-        break;
-      }
-    } else 
-      if (attDelta->IsKind(STANDARD_TYPE(TDF_DeltaOnRemoval))) {
-        att = attDelta->Attribute();
-        aGuid = att->ID();
-        indx1 = i;
-      }        
+  TDF_ListIteratorOfAttributeDeltaList anIt(attList);
+  for (; anIt.More(); anIt.Next()) { // append not-removal
+    Handle(TDF_AttributeDelta) attDelta = anIt.Value();
+    if (!attDelta->IsKind(STANDARD_TYPE(TDF_DeltaOnRemoval))) {
+      anOrderedList.Append(attDelta);
+    }
   }
-  if(indx1 && indx2) {
-    TDF_Array1OfAttributeIDelta anArray(1, attList.Extent());
-    itr.Initialize(attList);
-    for (i=1; itr.More(); itr.Next(), i++) 
-      anArray.SetValue(i, itr.Value());
-    Handle(TDF_AttributeDelta) attDelta1, attDelta2;
-    attDelta1 = anArray.Value(indx1);
-    attDelta2 = anArray.Value(indx2);
-    anArray.SetValue(indx1, attDelta2);
-    anArray.SetValue(indx2, attDelta1);
-    TDF_AttributeDeltaList attList2;
-    for(i=1; i<= anArray.Upper(); i++)
-      attList2.Append(anArray.Value(i));
-    theDelta->ReplaceDeltaList(attList2);
+  for (anIt.Initialize(attList); anIt.More(); anIt.Next()) { // append removal
+    Handle(TDF_AttributeDelta) attDelta = anIt.Value();
+    if (attDelta->IsKind(STANDARD_TYPE(TDF_DeltaOnRemoval))) {
+      anOrderedList.Append(attDelta);
+    }
   }
+  theDelta->ReplaceDeltaList(anOrderedList);
 }
 //=======================================================================
 //function : Undo
diff --git a/src/TDF/TDF_Data.hxx b/src/TDF/TDF_Data.hxx
index 5856a32f38..c9c3c2813f 100644
--- a/src/TDF/TDF_Data.hxx
+++ b/src/TDF/TDF_Data.hxx
@@ -147,7 +147,8 @@ protected:
 
 private:
 
-  //! Fixes order of Attributes' Deltas
+  //! Fixes order of Attributes' Deltas to perform undo/redo without exceptions:
+  //! puts OnRemoval deltas to the end of the list.
   void FixOrder(const Handle(TDF_Delta)& theDelta);
   
   //! Increments the transaction number and returns it.
diff --git a/tests/bugs/caf/bug29531 b/tests/bugs/caf/bug29531
new file mode 100644
index 0000000000..688f39c64c
--- /dev/null
+++ b/tests/bugs/caf/bug29531
@@ -0,0 +1,7 @@
+puts "==========="
+puts "OCC29531"
+puts "==========="
+
+pload QAcommands
+
+OCC29531 [locate_data_file bug29531_nist_ctc_02_asme1_ap242-2.stp]