diff --git a/ve/ve0100.cpp b/ve/ve0100.cpp
index 0b8070fab..cde40c561 100755
--- a/ve/ve0100.cpp
+++ b/ve/ve0100.cpp
@@ -189,6 +189,10 @@ bool TMotore_application::ss_handler( TSheet_field& ss, int r, KEY key )
           ss.check_row(r);
           ss.select(r);
         }
+        else
+          if ( key == K_TAB ) // modifica
+            set_curr_um(ss.sheet_mask());
+
   return TRUE;
 }
 
diff --git a/ve/velib.h b/ve/velib.h
index cb8b57592..807bf77ea 100755
--- a/ve/velib.h
+++ b/ve/velib.h
@@ -74,6 +74,7 @@ bool dummy_hndl(TMask_field& field, KEY key);
 bool condpag_hndl(TMask_field& field, KEY key);
 bool note_hndl(TMask_field& field, KEY key);
 bool data_hndl(TMask_field& field, KEY key);
+void set_curr_um(const TMask & m);
 
 class TDocumento_variable_field : public TVariable_field
 {                                           
diff --git a/ve/velib01.cpp b/ve/velib01.cpp
index 39f5820ed..288d11bef 100755
--- a/ve/velib01.cpp
+++ b/ve/velib01.cpp
@@ -387,6 +387,12 @@ bool liv_handler( TMask_field& f, KEY key )
     next.on_hit();
   }
   return TRUE;
+}  
+
+void set_curr_um(const TMask & m)
+{                
+  curr_um = m.get(FR_UMQTA);
+  curr_fc = -1.0;
 }
 
 bool umart_handler( TMask_field& f, KEY key )
@@ -404,7 +410,6 @@ bool umart_handler( TMask_field& f, KEY key )
     condv.set_riga(&row_mask);
     condv.set_anamag(anamag);
     condv.set_umart(umart);
-    condv.ricerca(TRUE);
 
     const TString16 um(f.get());
     real fc(1.0);
@@ -417,15 +422,26 @@ bool umart_handler( TMask_field& f, KEY key )
       if (umart.read() == NOERR)
       {
         real qta(row_mask.get_real(FR_QTA));
-        qta *= curr_fc;          
         fc = umart.get_real(UMART_FC);
+        if (curr_fc < ZERO)
+        {
+          umart.put(UMART_CODART, row_mask.get(FR_CODARTMAG));
+          umart.put(UMART_UM, curr_um);
+          if (umart.read() == NOERR)
+            curr_fc = umart.get_real(UMART_FC);
+          else
+            curr_fc = 1.0;
+        }
+        qta *= curr_fc;          
         qta /= fc;
+        qta.round(5);
         row_mask.set(FR_QTA, qta);
       }
         
     }
     curr_um = um;
     curr_fc = fc;
+    condv.ricerca(TRUE);
   }   
   return TRUE;
 }