With the stock stylesheet rule that sets list-style-type to none, the odd list is well disguised.
Code:
#navMain ul, #navSupp ul, #navCatTabs ul  {
	margin: 0;
	padding:  0.5em 0em;
	list-style-type: none;
	text-align: center;
	line-height: 1.5em;
	}
The OP's stylesheet eliminated that rule, making individual rules for the other elements and ignoring #navSupp which allowed it to take normal list behavior, probably unintentionally.