Most of us just turn it off, because it gets annoying. I saw it appear for a new user when I gave them a tiny sample process. No roles had been added.
Nothing in the solution had been added apart from a Business Object and a table. The dialog was obviously coming up because the default roles (which are created for all solutions) existed in other solutions.
Am I the only to notice that if this is the case, the dialog will come up every deployment for every solution regardless of content, and thus the dialog is completely worthless?