Table in Explorer looks fine - incorrectly sized in Firefox

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I have a table for text creating a 2 column list with no border. The layout is fine when viewed with Explorer 7 but with Firefox extra gaps appear between 6 of the phrases. The site is

Sorry, can't link yet! Any help would be great. I have no experience in web dev or design apart from this site I've made, so a non-jargon answer if possible will be appreciated!
some of the text seems to be wraped between "p" tags while the other are "span" enclosed

<p class="style1">Leukopenia<br />            </p>
so removing the "p" tag & "br" tag should fix that