updated page in menu – error resulted in total loss of menu page display

Mac OSX 10.6.8 on 3.2GHz intel. Safari 5.1.5. Nebulae, Gantry, menus

http://www.oldbike.eu/museum/

I wrote 2 new pages today. First uploaded in menu pages OK. But second one did not – selected it in ADD TO MENU box so that it appeared at the bottom of the menu items; then moved it up to its new location and clicked SAVE MENU as usual. But then error message appeared THE GIVEN OBJECT ID IS NOT THAT OF A MENU ITEM and i’ve now lost the entire menu display on the blog and access to my website pages. Only part of the menu list still appears in the wp-admin/nav-menus.php page.

I have copied the pages i wrote today to another blog. And I backed up this blog yesterday.

I’ve never reinstated a blog from a back-up. Will it recreate my menus to time of save? (Scared to try it!) And would it involve more re-writing of the blog than the 5 or 6 hours necessary to manually load all my 203 pages into the menu system?

I did have this error when I first changed to this theme/gentry/menu system. It happened repeatedly and the only way round it was to ‘save menu’ frequently with only 5 or 6 page insertions at a time. But this is more critical as obviously entire page menu rebuild is long-winded.

Thanks for your assistance

Colin