diff --git a/EXE_Exchange.cpp b/EXE_Exchange.cpp
index e1d6b38..318f00f 100644
--- a/EXE_Exchange.cpp
+++ b/EXE_Exchange.cpp
@@ -132,7 +132,7 @@ ExeImportStl( const string& sFilePath, double dScaleFactor)
 
 //-----------------------------------------------------------------------------
 bool
-ExeImportCnc( const string& sFilePath)
+ExeImportCnc( const string& sFilePath, int nFlag)
 {
    GseContext* pGseCtx = GetCurrGseContext() ;
    VERIFY_CTX_GEOMDB( pGseCtx, false)
@@ -144,7 +144,7 @@ ExeImportCnc( const string& sFilePath)
    PtrOwner<IImportCnc> pImpCnc( MyCreateImportCnc()) ;
    bOk = bOk && ! IsNull( pImpCnc) ;
    // eseguo l'importazione
-   bOk = bOk && pImpCnc->Import( sFilePath, pGseCtx->m_pGeomDB, nPartId) ;
+   bOk = bOk && pImpCnc->Import( sFilePath, pGseCtx->m_pGeomDB, nPartId, nFlag) ;
   // aggiorno stato file corrente
    pGseCtx->m_sFilePath = sFilePath ;
    ExeSetModified() ;
diff --git a/EXE_NstCreateFlatParts.cpp b/EXE_NstCreateFlatParts.cpp
index 96faa38..5266344 100644
--- a/EXE_NstCreateFlatParts.cpp
+++ b/EXE_NstCreateFlatParts.cpp
@@ -631,16 +631,17 @@ ExeAdjustFlatPartLayer( int nLayerId)
      // Passo all'entità successiva
       nId = nNextId ;
    }
-  // Unisco gli archi consecutivi con la stessa concavità
+  // Unisco gli archi consecutivi con la stessa concavità (escluse circonferenze)
    INTVECTOR vAccwIds ;
    INTVECTOR vAcwIds ;
    nId = pGeomDB->GetFirstInGroup( nLayerId) ;
    while ( nId != GDB_ID_NULL  &&  bOk) {
       const ICurveArc* pArc = GetCurveArc( pGeomDB->GetGeoObj( nId)) ;
       if ( pArc != nullptr) {
-         if ( pArc->GetAngCenter() > 0)
+         double dAngCen = pArc->GetAngCenter() ;
+         if ( dAngCen > EPS_ANG_SMALL  &&  dAngCen < ANG_FULL - EPS_ANG_SMALL)
             vAccwIds.emplace_back( nId) ;
-         else
+         else if ( dAngCen < - EPS_ANG_SMALL  &&  dAngCen > - ANG_FULL + EPS_ANG_SMALL)
             vAcwIds.emplace_back( nId) ;
       }
       nId = pGeomDB->GetNext( nId) ;
diff --git a/EgtExecutor.rc b/EgtExecutor.rc
index 450fe8b..9b90cdd 100644
Binary files a/EgtExecutor.rc and b/EgtExecutor.rc differ
diff --git a/LUA_Exchange.cpp b/LUA_Exchange.cpp
index 05066b8..f068c2f 100644
--- a/LUA_Exchange.cpp
+++ b/LUA_Exchange.cpp
@@ -15,6 +15,7 @@
 #include "stdafx.h"
 #include "LUA.h"
 #include "/EgtDev/Include/EXeExecutor.h"
+#include "/EgtDev/Include/EXeConst.h"
 #include "/EgtDev/Include/EGkLuaAux.h"
 #include "/EgtDev/Include/EgnStringUtils.h"
 
@@ -58,12 +59,14 @@ LuaImportStl( lua_State* L)
 static int
 LuaImportCnc( lua_State* L)
 {
-  // 1 parametro : path del file da importare
+  // 1 o 2 parametri : FilePath [, Flag]
    string sFilePath ;
    LuaCheckParam( L, 1, sFilePath)
+   int nFlag = EIC_FLAG_NONE ;
+   LuaGetParam( L, 2, nFlag) ;
    LuaClearStack( L) ;
   // apro il file
-   bool bOk = ExeImportCnc( sFilePath) ; 
+   bool bOk = ExeImportCnc( sFilePath, nFlag) ; 
   // restituisco il risultato
    LuaSetParam( L, bOk) ;
    return 1 ;