UPDATE:
I figured out how to deal with the problem. Adding stripslashes in:
admin-form.php
Line 50: <?php wp_editor(stripslashes($instructions->description),’description’); ?>
admin-table.php
Line 196: $html = wp_editor(stripslashes($item[‘text’]), ‘text’.$item[‘id’], array(‘textarea_rows’ => 5));
shortcode.php
Line 38: $html .= “<p>”.stripslashes($instructions->description).”</p>”;
I hope that it helps in someone else have to deal with the problem.
Again, thank for the wonderful work with this plugin. Simple but awesome.