Enter Key Functioning Like Tab Key

Hello Everyone,

I am experiencing an odd issue with my current install of Excel 2010. I have to use Amazon's Excel file for uploading tracking to their site. This file has an extremely annoying macro embedded in it that is necessary for it to work. The problem is that this macro seems to make the "Enter" key function like the "Tab" key, moving to the next column instead of the next row. This macro must have changed a global setting or something because now any file I open in Excel behaves the same way. As you can imagine this is very frustrating. Does anyone have any ideas how to reverse this behavior? I have attached the Amazon file for reference.

Thanks in advance for any help.

- Ian