I have a spreadsheet in 2000, most likely originally created in 97. It would not add a column of numbers properly using the sum formula. It also would not add when adding two cells or when highlighting a column of cells. Certain cells simply weren't being acted upon. I did verify that all cells were number format. I "fixed" this by retyping my numbers and everything seems to be fine. Has anyone else encountered this? Is there anything I should look out for? Should I scrap this workbook and start over? Thanks for your help. Dean