Use the constrain boxes in the Player when creating a timewarp to prevent values from changing when you change other values. For example, if you do not want to change the duration of the timewarp, enable the Constrain button for the Duration field. When you edit the speed value, in point, or out point with the Duration field constrained, the duration of the timewarp does not change.

To constrain a field:

1. Hold down Ctrl and click the Constrain box on the button you want to constrain.