diff --git a/Source/Parser/Functions/AchievementSetFunction.cs b/Source/Parser/Functions/AchievementSetFunction.cs
index 0e140bff..ccac490d 100644
--- a/Source/Parser/Functions/AchievementSetFunction.cs
+++ b/Source/Parser/Functions/AchievementSetFunction.cs
@@ -44,7 +44,24 @@ public override bool Evaluate(InterpreterScope scope, out ExpressionBase result)
                     set = context.Sets.FirstOrDefault(s => s.OwnerGameId == gameId.Value);
 
                 if (set == null)
+                {
                     set = context.Sets.FirstOrDefault(s => s.Title == title.Value);
+
+                    if (set != null)
+                    {
+                        if (id != null && id.Value > 0)
+                        {
+                            result = new ErrorExpression("Set with title '" + set.Title + "' already exists with id " + set.Id, id);
+                            return false;
+                        }
+
+                        if (gameId != null && gameId.Value > 0)
+                        {
+                            result = new ErrorExpression("Set with title '" + set.Title + "' already exists with game_id " + set.OwnerGameId, gameId);
+                            return false;
+                        }
+                    }
+                }
             }
 
             if (set == null)
@@ -77,17 +94,6 @@ public override bool Evaluate(InterpreterScope scope, out ExpressionBase result)
                     }
                 }
 
-                if ((set.Id != 0 || set.OwnerGameId != 0) &&
-                    set.Type.CanLoadWithBaseSet() &&
-                    context.Sets.Any(s => s.Id < AssetBase.FirstLocalId / 10))
-                {
-                    if (set.Id != 0)
-                        result = new ErrorExpression("Could not find set " + set.Id, id);
-                    else
-                        result = new ErrorExpression("Could not find set for game " + set.OwnerGameId, gameId);
-                    return false;
-                }
-
                 if (set.Id == 0)
                     set.Id = set.OwnerSetId = AssetBase.FirstLocalId / 10 + context.Sets.Count + 1;
                 if (set.OwnerGameId == 0)
diff --git a/Source/ViewModels/AchievementSetViewModel.cs b/Source/ViewModels/AchievementSetViewModel.cs
index db86560e..f70785d4 100644
--- a/Source/ViewModels/AchievementSetViewModel.cs
+++ b/Source/ViewModels/AchievementSetViewModel.cs
@@ -167,7 +167,18 @@ public void AssociateRACacheDirectory(string raCacheDirectory, List<AchievementS
                 foreach (var set in PublishedAssets.Sets)
                 {
                     if (!ReferenceEquals(_achievementSet, set))
-                        sets.Add(new AchievementSetViewModel(set, this));
+                    {
+                        var subset = sets.FirstOrDefault(s => s.AchievementSet.Id == set.Id);
+                        if (subset != null)
+                        {
+                            subset.PublishedAssets = PublishedAssets;
+                            subset.LocalAssets = LocalAssets;
+                        }
+                        else
+                        {
+                            sets.Add(new AchievementSetViewModel(set, this));
+                        }
+                    }
                 }
             }
         }
diff --git a/Source/ViewModels/GameViewModel.cs b/Source/ViewModels/GameViewModel.cs
index 9917af74..6ce078ee 100644
--- a/Source/ViewModels/GameViewModel.cs
+++ b/Source/ViewModels/GameViewModel.cs
@@ -684,8 +684,15 @@ public void AssociateRACacheDirectory(string raCacheDirectory)
         {
             RACacheDirectory = raCacheDirectory;
 
-            foreach (var set in _achievementSets)
-                set.AssociateRACacheDirectory(raCacheDirectory);
+            var achievementSets = new List<AchievementSetViewModel>(_achievementSets);
+            foreach (var set in achievementSets)
+            {
+                if (set.AchievementSet.Type == AchievementSetType.Core ||
+                    !set.AchievementSet.Type.CanLoadWithBaseSet())
+                {
+                    set.AssociateRACacheDirectory(raCacheDirectory, _achievementSets);
+                }
+            }
 
             var coreSet = _achievementSets.First();
             Title = coreSet.Title;
diff --git a/Source/ViewModels/Navigation/AchievementsFolderNavigationViewModel.cs b/Source/ViewModels/Navigation/AchievementsFolderNavigationViewModel.cs
index 34047134..1a46ffcb 100644
--- a/Source/ViewModels/Navigation/AchievementsFolderNavigationViewModel.cs
+++ b/Source/ViewModels/Navigation/AchievementsFolderNavigationViewModel.cs
@@ -36,5 +36,16 @@ protected override void OnPropertyChanged(PropertyChangedEventArgs e)
 
             base.OnPropertyChanged(e);
         }
+
+        public override bool Equals(object obj)
+        {
+            var that = obj as AchievementsFolderNavigationViewModel;
+            return (that != null && ReferenceEquals(_achievementSet, that._achievementSet));
+        }
+
+        public override int GetHashCode()
+        {
+            return base.GetHashCode();
+        }
     }
 }
diff --git a/Tests/Parser/Functions/AchievementSetFunctionTests.cs b/Tests/Parser/Functions/AchievementSetFunctionTests.cs
index 003ef9ea..bdde4423 100644
--- a/Tests/Parser/Functions/AchievementSetFunctionTests.cs
+++ b/Tests/Parser/Functions/AchievementSetFunctionTests.cs
@@ -167,7 +167,7 @@ public void TestExistingById()
         }
 
         [Test]
-        public void TestExistingByIdNotFound()
+        public void TestExistingByWrongId()
         {
             var harness = new AchievementSetFunctionHarness();
             harness.Context.Sets.Add(new AchievementSet
@@ -180,10 +180,10 @@ public void TestExistingByIdNotFound()
             });
             harness.Evaluate(
                 "// #ID=1234\r\n" +
-                "set_id = achievement_set(\"Game Bonus\", id=6666)",
+                "set_id = achievement_set(\"Banana\", id=6666)",
 
                 "2:10 achievement_set call failed\r\n" +
-                "- 2:43 Could not find set 6666"
+                "- 2:39 Set with title 'Banana' already exists with id 5555"
             );
         }
 
@@ -211,7 +211,7 @@ public void TestExistingByGameId()
         }
 
         [Test]
-        public void TestExistingByGameIdNotFound()
+        public void TestExistingByWrongGameId()
         {
             var harness = new AchievementSetFunctionHarness();
             harness.Context.Sets.Add(new AchievementSet
@@ -224,10 +224,10 @@ public void TestExistingByGameIdNotFound()
             });
             harness.Evaluate(
                 "// #ID=1234\r\n" +
-                "set_id = achievement_set(\"Game Bonus\", game_id=5555)",
+                "set_id = achievement_set(\"Banana\", game_id=5555)",
 
                 "2:10 achievement_set call failed\r\n" +
-                "- 2:48 Could not find set for game 5555"
+                "- 2:44 Set with title 'Banana' already exists with game_id 6666"
             );
         }