First things first
Make sure your installation of both Office 2008 & OS
X are fully updated (12.2.3 & 10.6.2 respectively). Repair Disk Permissions
using Apple's Disk utility (or comparable) app.
Once you've confirmed the above, if the Insert menu is still missing:
Go to View> Customize Toolbars & Menus. On the Toolbars & Menus page click
the name of the Worksheet Menu Bar (no its checkbox) , then click the Reset
button. If the Insert menu still isn't there after you OK out go back into
the same dialog box, but on the Commands page scroll to Built-in Menus in
the Categories List then drag the Insert menu from the Commands list to its
rightful place on the Worksheet Menu Bar (not the main menu itself).
HTH |:>)
Bob Jones
[MVP] Office:Mac