Access 97 and delphi 4 c/s with update


I am using a TDatabase and TQuery objects to connect to an Access 97
database. The problem I have is at design time I can set the connected
property to true and the active property to true and my app works but if I
don't set them and try  to do it at runtime I get an exception error 'Access
violation at address 0048ea2f'

Any help?