I cannot have left sidebar in Q&A plugin

Hi,

I installed Q&A plugin with "Twenty Twelve" default theme.

In Questions->Settings, there is a Page Layout control, where I can switch between right sidebar, left sidebar, or no sidebar.

When I try to switch to the "Content on right" layout (i.e., left sidebar), the theme layout of Q&A pages still remains the same with right sidebar.

Is it an expected behavior?

Thanks,
Dan