Newbie question: can't remove clip from timeline on Mac

Hi. I have tried searching for an answer but the documentation says if I select a clip in the timeline, I can just press delete and the selected clip will be removed. But that doesn't work. Also, Ctrl-Click brings up a menu that doesn't have the remove clip option*. So how do I remove a clip from the timeline?

I'm running 0.9.2 on a Mac. All help appreciated.

* the options available are:

Clip in Project Tree
Group Clips
Ungroup Clips
Split Audio
Set Audio Reference
Align Audio to Reference
Cut Clip
Copy
Paste Effects
Markers
Add Transition
Add Effect