Index: System.Data.SQLite/SQLiteTransaction.cs
==================================================================
--- System.Data.SQLite/SQLiteTransaction.cs
+++ System.Data.SQLite/SQLiteTransaction.cs
@@ -70,10 +70,14 @@
                     _cnn = null;
 
                     throw;
                 }
             }
+            else
+            {
+                throw new SQLiteException("Transaction is already active on this connection");
+            }
         }
 
         ///////////////////////////////////////////////////////////////////////////////////////////////
 
         #region IDisposable "Pattern" Members