Access forms appearance

Quite recently the appearance of Access 2003 forms has changed. Tabbed pages, once a fawnish colour (-2147483633) now appear as white, Control buttons are now shaded white with rounded corners where previously they had square corners. I have tested this on several PCs running Office 2003 with the same result. Has anyone else experienced this and if so have any idea what can be done to return to the previous style?