updated for version 7.4.567
Problem:    Non-ascii vertical separater characters are always redrawn.
Solution:   Compare only the one byte that's stored. (Thiago Padilha)
diff --git a/src/screen.c b/src/screen.c
index 290dd1b..bbf57b1 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -6062,7 +6062,7 @@
 	    int c;
 
 	    c = fillchar_vsep(&hl);
-	    if (ScreenLines[off_to] != c
+	    if (ScreenLines[off_to] != (schar_T)c
 # ifdef FEAT_MBYTE
 		    || (enc_utf8 && (int)ScreenLinesUC[off_to]
 						       != (c >= 0x80 ? c : 0))