category with posts missing from the sidebar

hi there,
i hope someone can help.
i have a slightly odd problem in that one of my categories is not appearing in my sidebar list despite having a post in it.

my url is:
http://marilynshampoo.co.uk/washandgogo

the category that is missing is ‘shampoo’s cupboard’ and you can see the post i have in it here:
http://marilynshampoo.co.uk/washandgogo/2006/12/11/rockstar-vanity-has-a-pretty-pink-phone/
and on the front page

i am calling it in my sidebar with:

<?php wp_list_cats(‘optioncount=1’); ?>

many thanks in advance for any help you can offer,

xxsxx