Pivot table limitations of Excel 2000

I have created a pivot table on excel 2000 by specifying a data in a separare sheet and creating a name. I use this sheet to create my pivot table, when I try to refresh the data it tells me that - "Excel Cannot make the change because there are too may row or column items. Drag atleast one row or column field off the pivot table, or to the page position. Alternatively, right click a field and then click hide or hide levels on the shortcut menu.
I tried hiding some columns on the pivot table, but that does not seem to help either. Please HELP