Recently I reinstalled Visio 2003 Enterprise Architecture edition and it started popping up the above mentioned error. I was not able to do any Database modeling kind of tasks since the options were not available. I goggled as usual and I found the same issue is being reported by many. The solution for this issue is uninstalling Visio Update patch KB947650. I did the same and it fixed my error
follow these steps :-
Control Panel –
Add or Remove Programs
Check “ Show Updates” check box in Add or Remove programs window
– MS Visio Enterprise Architect
Select KB947650 update and remove it.