excel4 macro warning

I have at one point, when opening my workbook without activating macro's, started getting a warning that my workbook contains an excel4 macro which cannot be deactivated??? What can this be in reference to. I don't have and never had anything but office97. I have at one point started using a selfmade VBAformula along with VBA macro's. but I'm not sure this is the exact time the problem started. Could the reference be to this?? The formula does keep working even when started without activating the macro's. If so, how can I get around this problem.