When you apply something to the timeline make sure to lit this anchor to freeze the object on a timeline (a new feature for iClone 8).
75% of original size (was 670x19) - Click to enlarge
But personally, I got used to a different technique. I keep "Object Related Track" in OFF state at all times (grayed out).
75% of original size (was 670x19) - Click to enlarge
This way, when you select something in the Scene Manager it is not applied to the timeline.
If you need to bring an object to the timeline, you click "Track Menu List" (icon to the left from "Object Related Track") and select what you need on the timeline.
Or do what I usually keep doing for years:
* Make sure "Object Related Track" is OFF
* Select an object (or a group of objects) in Scene manager.
* Click "Object Related Track" ON and immediately OFF (sort of double click).
This way nothing is applied to the timeline when you work with scene manager and you are in full control what you need to have at the timeline.