superfish change the width of a horizontal menu

superfish change the width of a horizontal menu

hi, i am using the jquery superfish menu at  http://users.tpg.com.au/j_birch/plugins/superfish/#getting-started. i cannot seem to modify the width of the menu items (or the <li>). how do i do this? i am using the superfish.css style sheet. i tried to modify the width by changing the values of a few classes (i.e. where it said 100% or had an em appended), but this did not help. any ideas?