calculated item not allowed in pivot
 

I am trying to do a pretty standard calculated item in a pivot in '03.
Getting the error that "The item cannot be added or modified. There may not
be enough memory, the maximum number of items allowed in a field may have
been reached, or if a VB macro is performing the operation, the macro may be
incorrect."

I know I am not out of memory. It's a small data set, and the table has no
other calcs. I don't think VB is running, as I closed down and then
restarted, and don't think that I have any macros to run in this workbook. I
am not sure about field item limits, but I only have 11 different items in
this field (about 3,500 records total), so would be surprised if that gets to
the limit. Any assistance?

--
Boris