Understand it this way. The VM notifications will all be shown. Like for example you got 13 new messages. As the front page only allows 10 or 12. The other one is in the next page. But since you visited your profile the notification will disappear. If the person who received the VM is not careful it can simply be missed by mistake. Happened to me tons and tons of times. So It wouldn't be a bother if you simply VM him/her again .
Simple thing to do is just to visit that person's profile and press the "view conversation" tab to see what your last message with him or her was. If you feel like you need an answer, hook him/her up again. If not, then well...