Anomaly in switching windows on different viewports in Unity

Question

My sample setting is as follows:

Viewport1 contains following window:

• Firefox A

Viewport2 contains following windows:

• Firefox B

• Gedit

When Viewport1 is shown and Firefox A has gained focus after Gedit, I can switch to Gedit via a single key stroke Alt-Tab.

However, after I press Alt-Tab again, Firefox B is switched. How can I achieve to switch to Firefox A without extra key stroke?

I am using Ubuntu 14.04 and Unity.

Edit 1: Bias alt-tab to prefer windows on the current viewport of ccsm conflicts with Switch between windows on all workspaces of Unity Tweak tool. Is Bias alt-tab to prefer windows on the current viewport of ccsm rendered to be useless?

Answer 1

From CCSM (install the compizconfig-settings-manager package if you don't have it):

Ubuntu Unity Plugin → Switcher → Uncheck "Bias alt-tab to prefer windows on the current viewport"