diff --git a/Config/Formulas.cs b/Config/Formulas.cs
index 971177d57..9357d5203 100644
--- a/Config/Formulas.cs
+++ b/Config/Formulas.cs
@@ -214,9 +214,9 @@ namespace Config
 		/// </summary>
 		public static double ErrorFromVolumes(double measuredVolume, double trueVolume)
 		{
-			if (trueVolume <= float.Epsilon)
+			if (-float.Epsilon <= trueVolume && trueVolume <= float.Epsilon)
 			{
-				if (measuredVolume <= float.Epsilon)
+				if (-float.Epsilon <= measuredVolume && measuredVolume <= float.Epsilon)
 				{
 					log.WarnFormat("ErrorFromVolumes({0},{1}) returns {2}", measuredVolume, trueVolume, -100.0);
 					return -100.0;
diff --git a/TBF/Properties/AssemblyInfo.cs b/TBF/Properties/AssemblyInfo.cs
index f937bb6b5..6dca06ec9 100644
--- a/TBF/Properties/AssemblyInfo.cs
+++ b/TBF/Properties/AssemblyInfo.cs
@@ -29,5 +29,5 @@ using System.Runtime.InteropServices;
 //      Build Number
 //      Revision
 //
-[assembly: AssemblyVersion("2.33.2064.0")]
-[assembly: AssemblyFileVersion("2.33.2064.0")]
+[assembly: AssemblyVersion("2.33.2065.0")]
+[assembly: AssemblyFileVersion("2.33.2065.0")]
diff --git a/TBF/UI/Bench/Metrology/MetrologyDlgPressMeterTab.cs b/TBF/UI/Bench/Metrology/MetrologyDlgPressMeterTab.cs
index de41809f2..7ebc3a23c 100644
--- a/TBF/UI/Bench/Metrology/MetrologyDlgPressMeterTab.cs
+++ b/TBF/UI/Bench/Metrology/MetrologyDlgPressMeterTab.cs
@@ -194,8 +194,9 @@ namespace TBF.UI.Bench.Metrology
             double correction;      /// Correction in default unit
             double error = 0;
 
-            if (subItem == 1 && Utils.TryParseEDouble(strValue, out oriMeasurement) && (measurement = Units.ConvertFrom(currentUnit, oriMeasurement)) >= 0)
+            if (subItem == 1 && Utils.TryParseEDouble(strValue, out oriMeasurement))
             {
+                measurement = Units.ConvertFrom(currentUnit, oriMeasurement);
                 (item.Tag as MeasurementCorrection).Measurement = measurement;
 
                 /// Update error (if possible)
diff --git a/TBF/UI/Bench/TestProfiles/TestProfilesCtrl.cs b/TBF/UI/Bench/TestProfiles/TestProfilesCtrl.cs
index 90637d337..bdf3dc6c0 100644
--- a/TBF/UI/Bench/TestProfiles/TestProfilesCtrl.cs
+++ b/TBF/UI/Bench/TestProfiles/TestProfilesCtrl.cs
@@ -140,28 +140,31 @@ namespace TBF.UI.Bench.TestProfiles
 		{
 			base.OkBtnClicked();
 
-            using (ITransaction transaction = session.BeginTransaction())
+            if (session != null && session.IsOpen)
             {
-                try
+                using (ITransaction transaction = session.BeginTransaction())
                 {
-                    foreach (var entity in ToBeRemovedItems) session.Delete(entity);
-                    ToBeRemovedItems.Clear();
-
-                    int itemNr = 0;
-                    foreach (var entity in MyItems)
+                    try
                     {
-                        (entity as Profile).ItemNr = itemNr++;
-                        session.SaveOrUpdate(entity);
-                    }
+                        foreach (var entity in ToBeRemovedItems) session.Delete(entity);
+                        ToBeRemovedItems.Clear();
 
-                    transaction.Commit();
-                    session.Flush();
-                }
-                catch (Exception exc)
-                {
-                    transaction.Rollback();
-                    log.ErrorFormat("Cannot save changes to DB: {0}", exc.Message);
-                    MessageBox.Show(Strings.Cannot_save_changes, Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
+                        int itemNr = 0;
+                        foreach (var entity in MyItems)
+                        {
+                            (entity as Profile).ItemNr = itemNr++;
+                            session.SaveOrUpdate(entity);
+                        }
+
+                        transaction.Commit();
+                        session.Flush();
+                    }
+                    catch (Exception exc)
+                    {
+                        transaction.Rollback();
+                        log.ErrorFormat("Cannot save changes to DB: {0}", exc.Message);
+                        MessageBox.Show(Strings.Cannot_save_changes, Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
+                    }
                 }
             }
 
diff --git a/TBF/UI/Procedures/ProceduresCtrl.cs b/TBF/UI/Procedures/ProceduresCtrl.cs
index 6a6ae977f..5881ae08f 100644
--- a/TBF/UI/Procedures/ProceduresCtrl.cs
+++ b/TBF/UI/Procedures/ProceduresCtrl.cs
@@ -268,28 +268,31 @@ namespace TBF.UI.Procedures
 		/// </summary>
 		public void OkBtnClicked()
 		{
-            using (ITransaction transaction = Session.BeginTransaction())
+            if (Session != null && Session.IsOpen)
             {
-                try
+                using (ITransaction transaction = Session.BeginTransaction())
                 {
-                    foreach (var entity in ToBeRemovedProcedures) Session.Delete(entity);
-                    ToBeRemovedProcedures.Clear();
-
-                    int itemNr = 0;
-                    foreach (var proc in AllProcedures)
+                    try
                     {
-                        (proc as Procedure).ItemNr = itemNr++;
-                        Session.SaveOrUpdate(proc);
-                    }
+                        foreach (var entity in ToBeRemovedProcedures) Session.Delete(entity);
+                        ToBeRemovedProcedures.Clear();
 
-                    transaction.Commit();
-                    Session.Flush();
-                }
-                catch (Exception exc)
-                {
-                    transaction.Rollback();
-                    log.ErrorFormat("Cannot save changes to DB: {0}", exc.Message);
-                    MessageBox.Show(Strings.Cannot_save_changes, Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
+                        int itemNr = 0;
+                        foreach (var proc in AllProcedures)
+                        {
+                            (proc as Procedure).ItemNr = itemNr++;
+                            Session.SaveOrUpdate(proc);
+                        }
+
+                        transaction.Commit();
+                        Session.Flush();
+                    }
+                    catch (Exception exc)
+                    {
+                        transaction.Rollback();
+                        log.ErrorFormat("Cannot save changes to DB: {0}", exc.Message);
+                        MessageBox.Show(Strings.Cannot_save_changes, Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
+                    }
                 }
             }