Excel 2003 Pivot Table Problem - Can No Longer Create Calculated Field
 

After some automatic downloads from Microsoft I note that my Excel 2003
Pivot Tables again work and can be refreshed with new data in the worksheets
(I was not able to do this after I downloaded something from Microsoft's
site). Now, the problem I have is that cannot insert a new calculated field
in any of my pivot tables.

In the past to insert a new calculated field I did the following: 1) in the
Insert Calculated Field Box, I selected the required fields from the list of
fields (Fields Box), hit the Inset Button, and inserted operands i.e.
divide, multiply, etc; 2) when the formula was completed, I'd hit the OK
button. The new calculated column would automatically appear in the pivot
table. Now, I create a formula, hit the OK button and nothing happens!

I thought it might have something to do with the file size exceeding a
certain size limitation, so I removed one file from the workbook, but I
still cannot create new calculated fields.

I would really appreciate any advice anyone can offer.
Peter