Bug#783957: here is a patch to fix this bug

[Selva Nair]

--- zonesigner    2012-06-28 06:25:28.000000000 -0400
+++ zonesigner_patched    2015-07-03 17:03:01.182687426 -0400
@@ -2973,6 +2973,7 @@
                 # Look through each line for the next
                 # line-with-a-number.
                 #
+               $ind++;
                 for(; $ind < @lines; $ind++)
                 {
                     my $line = $lines[$ind];


--
Selva