diff --git a/include/ccustio.c b/include/ccustio.c
index 6bd71543d..918dce2c4 100755
--- a/include/ccustio.c
+++ b/include/ccustio.c
@@ -59,25 +59,24 @@ semres                : flag per l'ok delle operazioni sui semafori
 BOOLEAN test_share()
 
 {
-  static BOOLEAN share_active = TRUE;
 #ifdef DOS
-  static BOOLEAN to_test = TRUE;
+  static BOOLEAN share_active = 2;
   
-  if (to_test)
+  if (share_active == 2)
   {
-    to_test = FALSE;
-   
     share_active = CGetAut(MUAUT);
     if (share_active)
     {
-      int f = sopen("net.ini", O_RDONLY, SH_DENYNO, S_IREAD);
+      int f = open("net.ini", O_RDONLY, SH_DENYNO, S_IREAD);
    
       share_active = f != -1;
       if (f != -1) close(f);    
     }
   }
-#endif
   return share_active; 
+#else
+  return TRUE; 
+#endif
 }