Glenn, as far as i am aware, the elements for the "highlight" action of the navbar should reside in the "MouseOver layer" - these are also usually hidden with a "red eye" in the page and layer gallery, i have seen copy and pasting destroy the layer positions on my own creations for some reason, worth a look - and even the repeat on all pages can screw up. - do you have the nav bar set as a "site navigation bar" in the navbar settings? - not too familiar with the paypal buttons or its possible negative interaction with the navbars.

One of the Gurus will be along soon i have no doubt and offer some more in depth help, the above is what i check for when the navbars play up.

Ray