WP3 menus help please

I am not sure if this is possible, hence my post 🙂

I am using WP3 menu system. I have created 2 pages – 1 for the category of ‘books’ (this is populated with all book posts’ and one for the category of ‘blog’ (this has all the others posts dislayed) both these cats are now in the WP menu.

Menu works as expected – when on books page ‘books’ highlighted and blogs highlighted on ‘blogs’ page.

Now what I am desperately trying to do is have the menu highlighted to the correct menu item (books or blogs) when viewing a post on a single.php page.

Can anyone offer any guidance on this as I have trawled the ‘net and had no luck.

In the past I have used something like this: http://paste-it.net/public/o76011d/ but it don’t work with the menus.

I may even be able to muster a little cash if I can get the right solution – not much though 🙂

Thanks guys!