Nav bar not updating

[masque]

I have a fairly simple 12 - 13 page site. All but two pages are accessed from a drop down menu on the main nav bar which was produced in Webstyle 4 and FrontPage Office 2003.
If I update the menu, ie for a spelling mistake in one instance, the menu update is saved and when opened in Frontpage as a preview looks fine with the mistake corrected but when the site is uploaded the correction does not appear.
I find the only way to correct mistakes in the nav bar is to delete it and start again.
Can anyone suggest where I might be going wrong.
Derek