This is on r85, haven't seen this before, but may be an old bug
I have an object with 4 sine behaviors. At the event list, I have 4 events that sets their magnitudes, but each time I edit any of these events, it sets the event for the 4th sine behavior
Eg:
Object: Sine1: set magnitude to 20
Object: Sine2: set magnitude to 20
Object: Sine3: set magnitude to 20
Object: Sine4: set magnitude to 20
Then I double click the first event, and change it to 25
Object: Sine4: set magnitude to 25
Object: Sine2: set magnitude to 20
Object: Sine3: set magnitude to 20
Object: Sine4: set magnitude to 20