Excel 2003 spreadsheet not working in Excel 2007. :(

I have an Excel Spreadsheet 2003.
This has macros that do a few things for me.

I've had Office 2007 installed.
It doesn't work.
The spreadhseet has buttons: the buttons don't function as buttons.

I've no idea what's worng.

I've tried playing around with the settings and have got it to warn me if it's turning off a macro.
Still no joy.

I can't see anywhere else that would be relevant to change the settings on.

Any help would be appreciated.

Thanks.


OM