The Linktarget issues reported under "AA" Accessibility are caused by having multiple links on a page that have the same "name" but link to different pages.

A good example I saw recently was on a fashion retailers site.  They had tabs under the banner for things like Men, Women, Denim, Lifestyle.  When you hover over a tab you get a hover box appear with the sub categories for the tab.  The problem was that under both the Men and Women tabs you had sub-categories like Shirts, Shorts, Footwear and Denim.  When you moved the mouse over a sub-category the hover-box came up with just the same word.  So someone using a screen reader reading out the links on the page would struggle to know whether they'd end up at women's shorts or men's shorts.  With Denim it's even worse because the link from the Denim tab as well as the ones under men's and women were all called Denim.

An easy way to remedy this is to use a Title attribute

title="Women's Shorts" href="Store/Browse.aspx?DepartmentId=Womens&amp;CategoryId=Womens_Shorts">Shorts</a>

Most of your navigation will probably be in your Templates so it's a relatively minor change that will have a big impact on the whole of your site