Action on one sheet is performed on all

[etown2006]

Hi,
When I perform an action on one sheet that action is repeated on every sheet So for example if I hide row 8 on sheet 2, row 8 is automatically hidden on every sheet. If I type in 3 into cell A2, 3 appears in cell A2 on every sheet. What is going on? How do I turn this off?
Thanks for your help!

[bentleybob]

You probably have Group mode enabled. [n Excel 2007, it shows this in the title bar at the very top.