diff -ur iscan-2.26.2.orig/lib/pngstream.cc iscan-2.26.2/lib/pngstream.cc
--- iscan-2.26.2.orig/lib/pngstream.cc	2011-01-26 08:53:27.000000000 +0200
+++ iscan-2.26.2/lib/pngstream.cc	2011-09-26 18:51:26.151722441 +0300
@@ -76,7 +76,7 @@
         set_error_handler (_png, _info);
 
         lib->write_flush (_png);
-        if (!_footer && _png->num_rows == _png->flush_rows)
+        if (!_footer && png_get_current_row_number(_png) == png_get_current_pass_number(_png))
           {
             lib->write_end (_png, _info);
             _footer = true;