diff --git a/src/Umbraco.Core/Cache/DefaultRepositoryCachePolicy.cs b/src/Umbraco.Core/Cache/DefaultRepositoryCachePolicy.cs
index fda57cefee..a5777a5775 100644
--- a/src/Umbraco.Core/Cache/DefaultRepositoryCachePolicy.cs
+++ b/src/Umbraco.Core/Cache/DefaultRepositoryCachePolicy.cs
@@ -35,8 +35,6 @@ namespace Umbraco.Core.Cache
 
         public void CreateOrUpdate(TEntity entity, Action<TEntity> persistMethod)
         {
-            var cacheKey = GetCacheIdKey(entity.Id);
-
             try
             {
                 persistMethod(entity);
@@ -44,7 +42,12 @@ namespace Umbraco.Core.Cache
                 //set the disposal action                
                 SetCacheAction(() =>
                 {
-                    Cache.InsertCacheItem(cacheKey, () => entity);
+                    //just to be safe, we cannot cache an item without an identity
+                    if (entity.HasIdentity)
+                    {
+                        Cache.InsertCacheItem(GetCacheIdKey(entity.Id), () => entity);
+                    }
+                    
                     //If there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
                     Cache.ClearCacheItem(GetCacheTypeKey());
                 });
@@ -57,7 +60,7 @@ namespace Umbraco.Core.Cache
                 {
                     //if an exception is thrown we need to remove the entry from cache, this is ONLY a work around because of the way
                     // that we cache entities: http://issues.umbraco.org/issue/U4-4259
-                    Cache.ClearCacheItem(cacheKey);
+                    Cache.ClearCacheItem(GetCacheIdKey(entity.Id));
 
                     //If there's a GetAllCacheAllowZeroCount cache, ensure it is cleared
                     Cache.ClearCacheItem(GetCacheTypeKey());
@@ -188,7 +191,14 @@ namespace Umbraco.Core.Cache
         /// <param name="entity"></param>
         protected virtual void SetCacheAction(string cacheKey, TEntity entity)
         {
-            SetCacheAction(() => Cache.InsertCacheItem(cacheKey, () => entity));
+            SetCacheAction(() =>
+            {
+                //just to be safe, we cannot cache an item without an identity
+                if (entity.HasIdentity)
+                {
+                    Cache.InsertCacheItem(cacheKey, () => entity);
+                }
+            });
         }
 
         /// <summary>
@@ -214,7 +224,11 @@ namespace Umbraco.Core.Cache
                     foreach (var entity in entityCollection.WhereNotNull())
                     {
                         var localCopy = entity;
-                        Cache.InsertCacheItem(GetCacheIdKey(entity.Id), () => localCopy);
+                        //just to be safe, we cannot cache an item without an identity
+                        if (localCopy.HasIdentity)
+                        {
+                            Cache.InsertCacheItem(GetCacheIdKey(entity.Id), () => localCopy);
+                        }
                     }
                 }
             });
diff --git a/src/Umbraco.Core/Services/LocalizedTextService.cs b/src/Umbraco.Core/Services/LocalizedTextService.cs
index 886fa47cbf..84ff3b745b 100644
--- a/src/Umbraco.Core/Services/LocalizedTextService.cs
+++ b/src/Umbraco.Core/Services/LocalizedTextService.cs
@@ -112,19 +112,15 @@ namespace Umbraco.Core.Services
                 }
 
                 //convert all areas + keys to a single key with a '/'
-                var areas = xmlSource[culture].Value.XPathSelectElements("//area");
-                foreach (var area in areas)
+                result = GetStoredTranslations(xmlSource, culture);
+
+                //merge with the english file in case there's keys in there that don't exist in the local file
+                var englishCulture = new CultureInfo("en-US");
+                if (culture.Equals(englishCulture) == false)
                 {
-                    var keys = area.XPathSelectElements("./key");
-                    foreach (var key in keys)
-                    {
-                        var dictionaryKey = string.Format("{0}/{1}", (string) area.Attribute("alias"), (string) key.Attribute("alias"));
-                        //there could be duplicates if the language file isn't formatted nicely - which is probably the case for quite a few lang files
-                        if (result.ContainsKey(dictionaryKey) == false)
-                        {
-                            result.Add(dictionaryKey, key.Value);
-                        }
-                    }
+                    var englishResults = GetStoredTranslations(xmlSource, englishCulture);
+                    foreach (var englishResult in englishResults.Where(englishResult => result.ContainsKey(englishResult.Key) == false))
+                        result.Add(englishResult.Key, englishResult.Value);
                 }
             }
             else
@@ -153,6 +149,25 @@ namespace Umbraco.Core.Services
             return result;
         }
 
+        private Dictionary<string, string> GetStoredTranslations(IDictionary<CultureInfo, Lazy<XDocument>> xmlSource, CultureInfo cult)
+        {
+            var result = new Dictionary<string, string>();
+            var areas = xmlSource[cult].Value.XPathSelectElements("//area");
+            foreach (var area in areas)
+            {
+                var keys = area.XPathSelectElements("./key");
+                foreach (var key in keys)
+                {
+                    var dictionaryKey = string.Format("{0}/{1}", (string)area.Attribute("alias"),
+                        (string)key.Attribute("alias"));
+                    //there could be duplicates if the language file isn't formatted nicely - which is probably the case for quite a few lang files
+                    if (result.ContainsKey(dictionaryKey) == false)
+                        result.Add(dictionaryKey, key.Value);
+                }
+            }
+            return result;
+        }
+
         /// <summary>
         /// Returns a list of all currently supported cultures
         /// </summary>
diff --git a/src/Umbraco.Web/Editors/BackOfficeController.cs b/src/Umbraco.Web/Editors/BackOfficeController.cs
index 412e09ec52..4ffe57a924 100644
--- a/src/Umbraco.Web/Editors/BackOfficeController.cs
+++ b/src/Umbraco.Web/Editors/BackOfficeController.cs
@@ -5,6 +5,7 @@ using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
 using System.Web.Configuration;
@@ -100,7 +101,8 @@ namespace Umbraco.Web.Editors
             var cultureInfo = string.IsNullOrWhiteSpace(culture)
                 //if the user is logged in, get their culture, otherwise default to 'en'
                 ? Security.IsAuthenticated()
-                    ? Security.CurrentUser.GetUserCulture(Services.TextService)
+                    //current culture is set at the very beginning of each request
+                    ? Thread.CurrentThread.CurrentCulture
                     : CultureInfo.GetCultureInfo("en")
                 : CultureInfo.GetCultureInfo(culture);