diff --git a/Asterisk.2013/Asterisk.NET/Common.cs b/Asterisk.2013/Asterisk.NET/Common.cs
index 9111467..e88a0ef 100644
--- a/Asterisk.2013/Asterisk.NET/Common.cs
+++ b/Asterisk.2013/Asterisk.NET/Common.cs
@@ -18,8 +18,8 @@ namespace AsterNET
         /// <summary>Line separator</summary>
         public const string LINE_SEPARATOR = "\r\n";
 
-        public static Regex ASTERISK_VERSION = new Regex("^Asterisk\\s+\\D*([0-9]+.[0-9]+.[0-9]+|[1-9][0-9]-r[0-9]+).*$", 
-                    RegexOptions.Compiled | RegexOptions.IgnoreCase);
+        public static Regex ASTERISK_VERSION = new Regex( "^Asterisk\\s+\\D*([0-9]+.[0-9]+.[0-9]+|[1-9][0-9]-r[0-9]+|[0-9]+.[0-9]+-cert[0-9]).*$",
+                    RegexOptions.Compiled | RegexOptions.IgnoreCase );
 
         public static Regex SHOW_VERSION_FILES_PATTERN = new Regex("^([\\S]+)\\s+Revision: ([0-9\\.]+)");
         public static char[] RESPONSE_KEY_VALUE_SEPARATOR = {':'};
diff --git a/Asterisk.2013/Asterisk.NET/Manager/ManagerConnection.cs b/Asterisk.2013/Asterisk.NET/Manager/ManagerConnection.cs
index 0c1eb81..2300c32 100644
--- a/Asterisk.2013/Asterisk.NET/Manager/ManagerConnection.cs
+++ b/Asterisk.2013/Asterisk.NET/Manager/ManagerConnection.cs
@@ -2162,12 +2162,16 @@ namespace AsterNET.Manager
 			}
 
             IActionVariable actionVar = action as IActionVariable;
-            if(actionVar != null && actionVar.GetVariables().Count > 0)
+            if ( actionVar != null )
             {
-                sb.Append(string.Concat("Variable: ", Helper.JoinVariables(actionVar.GetVariables(), VAR_DELIMITER, "="), Common.LINE_SEPARATOR));
+                var variables = actionVar.GetVariables();
+                if ( variables != null && variables.Count > 0 )
+                {
+                    sb.Append( string.Concat( "Variable: ", Helper.JoinVariables( actionVar.GetVariables(), VAR_DELIMITER, "=" ), Common.LINE_SEPARATOR ) );
+                }
             }
 
-			sb.Append(Common.LINE_SEPARATOR);
+            sb.Append(Common.LINE_SEPARATOR);
 			return sb.ToString();
 		}
 		#endregion