When working with the timeline and zooming in and out using option, it's very glitchy. Doesn't stick and jumps back and forth from zoom in to zoom out. The only way I've been able to have the zoom stick is to move the cursor outside of the timeline before I let go of the option key. 

Les problèmes de zoom sont facilement corrigés.
Allez dans la timeline, selectionner le point zoom précédent , copier, aller au second point zoom , reculer de.un pas, et coller.

是啊时间线超出屏幕还要回调！