Offset text in Firefox 3

Similar to a recent thread, cells in tables on my pages are offset in FF3 but not in IE7. Examples are:http://all-const.com/projects/additi...atino_main.htmhttp://all-const.com/projects/new/new_main.htm
and so on in this site.
I can't find any obvious coding errors in the html. What could be causing this?
Thanks