Disable updating of the menu widget when working with Muse file?

First of all thank you Adobe for creating Muse - I really like it a lot!
My question:
when I work on my website with 250+ pages, it strains the performance to make even the slightest changes to the page structure. I work with two Masters each with much the same horisontal menu widget.
Adding, deleting and rearranging pages makes the PC (Windows 7 laptop of some but not awesome power) make a halt and take a deep breathe for some seconds. It really interupts the flow of working.
A crude work around for this is to removing the menu widget in the two masters and put it into a new master page, containing only the copied menu from the two other masters and keeping the rest of the header in place on the original masters to use for aligning on the pages. This way, only one page has to update when working with adding, deleting and rearranging pages.
I have tried to look for a preference to disable updating the Menu widget when working on the page structures and just enable it the update again when the work is done? does it exist? else I would recommend it strongly :-) Since my work around is a bit tricky/risky to use after publishing ;-)
Again, thanks a lot for this nice program. Being a selftought CS (now CCC) user I like the ease of control of the webdesign you can get with Muse (at the dispence of other features of course - if you ever wanted to add some sort of database-lookup feature it would be MUCH appreciated. One workaround is to use iframe and an external search/lookup page, that returns results with links back to parent pages. A bit funny construction though :-) ).
BR
M. Hecquet