Thank you so much for this info esmi!
It would be nice if that was added to this part of the codex:
http://codex.wordpress.org/Dynamic_Menu_Highlighting
@esmi
Thanks so much for posting your code, this is exactly what I have been looking for, all I have found through Google has over complicated it.
I don’t know the answer, but I was searching to see if I could find this somewhere online, and came across your question. Have you found a solution?