A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
I tried that at the very first with no effect on my problem, also I fight shy of updates for their own sake unless there is a pressing bug/security problem. However, my local Apple retailer sent me this which appears to have cured the problem.
If you have tried a new user account and Excel works ok in that account it must be something in the original account.
I would suggest looking in ~/Library/. In Application Support delete the Microsoft folder. In Caches delete anything starting with com.microsoft or Microsoft Office. In Preferences delete anything com.microsoft or Microsoft or Office.
You should not need to reinstall Office as it is working in another user.
Regards Bob
My reply
I had already done this as well as completely uninstalling MS Office manually with no effect. However, I did as you suggested (again) and it is now working as it should so I must have missed something before.
Thanks for getting back to me and emphasising the must - which ultimately made me do it again and seems to have cured the problem.
Thanks to you both for taking an interest in my (hopefully never to return) problem. Nostrebor