I'm having this problem with the Windows version of OACS 5.1.5 from Project/Open. I.e. Registered Users can read posts and create new posts, but can't reply to them.
Main Site » Forums » Administration » Testing Forum Permissions
Under the specific forum's (called Testing Forum)permissions for Registered Users, Read and Create are checked.
If I go through "Main Site » Permissions » Permissions for Testing Forum" as I think is suggested above, I see that the inherited permissions are Read and create for everyone. Under the "Direct Permissions" below, if I check the forum_write box and click on "Grant Permission" I get to the Grant Permissions page. However selecting Registered Users and hitting OK throws me back to the previous page. But the Registered Users still can't reply to posts.
Restarting the three services: AOLServer, PostgresQL, and Cygwin doesn't help.
