diff --git a/screen.c b/screen.c
index 19bf4a1..c044125 100644
--- a/screen.c
+++ b/screen.c
@@ -105,7 +105,6 @@ static void addch(H3270 *session, int baddr, unsigned char c, unsigned short att
 	session->text[baddr].attr = attr;
 
 	session->update(session,baddr,c,attr,baddr == session->cursor_addr);
-
 }
 
 LIB3270_EXPORT int lib3270_get_element(H3270 *h, int baddr, unsigned char *c, unsigned short *attr)
@@ -303,7 +302,9 @@ void screen_update(H3270 *session, int bstart, int bend)
 	a  		= color_from_fa(fa);
 	fa_addr = find_field_attribute(session,bstart); // may be -1, that's okay
 
+#ifdef WIN32
 	trace("%s start=%d end=%d",__FUNCTION__,bstart,bend);
+#endif // WIN32
 
 	for(baddr = bstart; baddr < bend; baddr++)
 	{
@@ -350,6 +351,10 @@ void screen_update(H3270 *session, int bstart, int bend)
 		}
 	}
 
+#ifdef WIN32
+	trace("%s first=%d last=%d",__FUNCTION__,first,last);
+#endif // WIN32
+
 	if(first >= 0)
 	{
 		int len = (last - first)+1;
@@ -361,6 +366,9 @@ void screen_update(H3270 *session, int bstart, int bend)
 				len++;
 		}
 
+#ifdef WIN32
+		trace("%s first=%d last=%d len=%d changed=%p",__FUNCTION__,first,last,len,session->changed);
+#endif // WIN32
 		session->changed(session,first,len);
 	}
 
--
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