I'd really like to know how to do this too. I spent several hours trying to figure out the actions and roles with absolutely no luck. After much studying of the code, I did what I thought would work, but it had no effect, specifically: add workflow.Role_AssigneeSubquery_RegisteredUsers to the roles that are allowed to do useful things (like comment on issues). In short, I clearly do not understand the workflow model at all, or how to modify it.
Obviously, some folks believe users being able to comment on issues makes sense, as that is the way the OpenACS.org bug-tracker works. But I checked out the OpenACS bug tracker from CVS and it is clearly a very different version than 5.1.5, as there is no workflow code at all.
If anyone knows how to do this with the current codebase, it'd make me very happy.
Sorry I can't be of any help, Anny, I just wanted to commiserate.
