If possible you should put the menu in a master layout that both of your layouts use
Hi Bart,
It seems like the situation you outlined should work like you expect. It may be a good idea to create a support ticket just to track this issue. In the short term, someone has already gone through the trouble of creating the ugly javascript solution and wrapped it in a nice widget. Check out the following widget and see if it helps you out:
https://github.com/tieniber/ActiveMenuSelector