Thanks for the reply.
I am using the version 8.0.8003.
Author (user1) of the review is waiting for the "Any Activity Occurs".
Please note that the role setting "Phase-change waits for "finished"" is set to Yes for both Author and Reviewer roles.
I think your steps are correct, but just to be sure let me reiterate them:
1. Author (user1) creates a review, adds user2 as a reviewer and begins the review.
2. Author sets his state to Waiting and chooses "Any Activity Occurs"
3. Reviewer (user2) clicks on Approve button.
Result: Both users are changed to the Active state.
Expected result: Just author is changed to the Active state and Reviewer stays in the Approved state.
