[@netweb Keymaster 13 years, 9 months ago]

Are you referring to Mingle Forums?

If so I could not repro this with bbPress 2.2.3 and Mingle Forums 1.0.33.3

• WordPress Role = Administrator | bbPress Role = Keymaster
• WordPress Role = Subscriber | bbPress Role = Moderator
• WordPress Role = Subscriber | bbPress Role = Participant
• WordPress Role = Subscriber | bbPress Role = Spectator

The above was all I tested but each works as expected:
https://codex.bbpress.org/bbpress-user-roles-and-capabilities/