Problem with Multiple Navigation

On site – http://www.denniscompany.com/blog/ I am using the Mystique theme but I want the pages on 1 Nav bar and the Categories on a 2nd Nav bar (as is set up) The problem is when I access a category (paint) everything looks good, but if I select a category (pets) the “About” page is highlighted in the Nav as if I was on that page.

Any ideas as to why certain categories are telling the code that the current page is either the Welcome or About page?

Thanks for any suggestions.