diff --git a/src/Orchard/Data/SessionConfigurationCache.cs b/src/Orchard/Data/SessionConfigurationCache.cs
index 4190e31c4..f774a0118 100644
--- a/src/Orchard/Data/SessionConfigurationCache.cs
+++ b/src/Orchard/Data/SessionConfigurationCache.cs
@@ -105,6 +105,9 @@ namespace Orchard.Data {
         private Hash ComputeHash() {
             var hash = new Hash();
 
+            hash.AddString(_shellSettings.DataProvider);
+            hash.AddString(_shellSettings.DataTablePrefix);
+            hash.AddString(_shellSettings.DataConnectionString);
             hash.AddString(_shellSettings.Name);
 
             // We need to hash the assemnly names, record names and property names
diff --git a/src/Orchard/Utility/Hash.cs b/src/Orchard/Utility/Hash.cs
index 83f60db1b..49622d72f 100644
--- a/src/Orchard/Utility/Hash.cs
+++ b/src/Orchard/Utility/Hash.cs
@@ -12,6 +12,8 @@ namespace Orchard.Utility {
         public string Value { get { return _hash.ToString(); } }
 
         public void AddString(string value) {
+            if ( string.IsNullOrEmpty(value) )
+                return;
             _hash += value.GetHashCode();
         }