Another error like this occurs if you don't keep Sidewise running (I don't since it isn't compatible with New Tabs Always last).

If you disable Sidewise and then browse in Chrome, tabs that were previously open before you disabled Sidewise will be shown as hibernated, tabs that are new work, but some tabs that were open will show in their current position as hibernated and then jump to the new position.

I would also like to see an option that disabled the tab hierarchy and allowed it to work with New Tabs Always Last.