diff --git a/SteamWareLib/memLayer.cs b/SteamWareLib/memLayer.cs
index 5effe1a..78913cd 100644
--- a/SteamWareLib/memLayer.cs
+++ b/SteamWareLib/memLayer.cs
@@ -260,14 +260,16 @@ namespace SteamWare
             resetAppConf();
           }
           // provo a leggere da DICT
-          try
+          if (AppConf.ContainsKey(chiave))
           {
-            answ = AppConf[chiave];
-          }
-          catch (Exception exc)
-          {
-            logger.lg.scriviLog(string.Format("Errore in lettura AppConf[{0}] durante configDbVal{1}{2}", chiave, Environment.NewLine, exc), tipoLog.EXCEPTION);
-
+            try
+            {
+              answ = AppConf[chiave];
+            }
+            catch (Exception exc)
+            {
+              logger.lg.scriviLog(string.Format("Errore in lettura AppConf[{0}] durante configDbVal{1}{2}", chiave, Environment.NewLine, exc), tipoLog.EXCEPTION);
+            }
           }
         }
       }
@@ -290,13 +292,17 @@ namespace SteamWare
     public bool cdvb(string chiave)
     {
       bool answ = false;
-      try
+      string sVal = configDbVal(chiave);
+      if (sVal != "")
       {
-        answ = Convert.ToBoolean(configDbVal(chiave));
-      }
-      catch (Exception exc)
-      {
-        logger.lg.scriviLog(string.Format("Errore in lettura chiave [{0}] durante cdvb{1}{2}", chiave, Environment.NewLine, exc), tipoLog.EXCEPTION);
+        try
+        {
+          answ = Convert.ToBoolean(configDbVal(chiave));
+        }
+        catch (Exception exc)
+        {
+          logger.lg.scriviLog(string.Format("Errore in lettura chiave [{0}] durante cdvb{1}{2}", chiave, Environment.NewLine, exc), tipoLog.EXCEPTION);
+        }
       }
       return answ;
     }
@@ -308,13 +314,17 @@ namespace SteamWare
     public int cdvi(string chiave)
     {
       int answ = -1;
-      try
+      string sVal = configDbVal(chiave);
+      if (sVal != "")
       {
-        answ = Convert.ToInt32(configDbVal(chiave));
-      }
-      catch (Exception exc)
-      {
-        logger.lg.scriviLog(string.Format("Errore in lettura chiave [{0}] durante cdvi{1}{2}", chiave, Environment.NewLine, exc), tipoLog.EXCEPTION);
+        try
+        {
+          answ = Convert.ToInt32(configDbVal(chiave));
+        }
+        catch (Exception exc)
+        {
+          logger.lg.scriviLog(string.Format("Errore in lettura chiave [{0}] durante cdvi{1}{2}", chiave, Environment.NewLine, exc), tipoLog.EXCEPTION);
+        }
       }
       return answ;
     }
@@ -479,12 +489,15 @@ namespace SteamWare
     public string QSS(string nome)
     {
       string answ = "";
-      try
+      if (HttpContext.Current.Request.QueryString[nome] != null)
       {
-        answ = HttpContext.Current.Request.QueryString[nome].ToString().Trim();
+        try
+        {
+          answ = HttpContext.Current.Request.QueryString[nome].ToString().Trim();
+        }
+        catch
+        { }
       }
-      catch
-      { }
       return answ;
     }
     /// <summary>
@@ -1071,7 +1084,6 @@ namespace SteamWare
     /// svuota una variabile dalla Cache
     /// </summary>
     /// <param name="nomeVar"></param>
-    /// <param name="nome"></param>
     public bool emptyCacheVal(string nomeVar)
     {
       bool _done = false;
@@ -1164,6 +1176,7 @@ namespace SteamWare
         catch (Exception exc)
         {
           answ = new Dictionary<string, string>();
+          logger.lg.scriviLog(string.Format("Errore in tabelleInCache{0}{1}", Environment.NewLine, exc));
         }
         return answ;
       }