Hello and help
A collegue has asked me to look at an Excel ribbon issue.

The Excel file had a ribbon until recently, nobody knows how but the ribbon
has dissapeared. I have zipped the file and looked through its file structure
and the custonUI folder is missing.
MS Off2007 Custom UI Editor shows no xml in the file. I copy some code into
it but when I save it the follwing message appears.

''Cannot add part for the specified URI because it is already in the
package.''

It looks like Excel thinks it is there but nothing can see it. What do I do
next????

Many Thanks