Scroll Lock?

I'm running Excell 2004 for Mac, version 11.5, running on an Intel MacBook 
under OS 10.5.4. 
When I use the arrow keys on the keyboard, the screen scrolls across but
the 
cursor does not move from one cell to the next, which is very frustrating.

At the bottom of the sheet, there is a green button next to SCRL - I think

this means I have Scroll Lock on? How do I turn it off?? I can't find 
anything in the help files. 

Thank you