I have a simple fill in the blank one page spreadsheet that I have used every week for over two years (very few calculations, mostly just text). As time goes by, I have noticed that it becomes very slow to react to movement within the spreadsheet. When I press page down or down arrow which makes the spreadsheet scroll, it takes several seconds to move each line. Other spreadsheets do not have this problem. My question is: Is there a known problem within Excel or its code, that causes it to remember historical changes or increase its calcuations in documents that are old and have been modified thousands of times?