Object level security: User in multiple security roles

Hi there, 

I've set up Object Level Security on a table in my data model, published it, and allocated our distribution groups to the two security roles I've created (one with access, one without). 

In our organizations, people can be in several distribution groups, and as so I've run into a problem, when a person is in a distribution group with access and one without access. My users get the error message below. Should I set up "dynamic security configuration" for it to work? And if so, does anyone have some good links to material on how to do that?