un-/indent doesn't obey column selection

If I have lines of code that are tabulated for readability, like:
FLOATS_EQUAL( expected.foo, actual.foo, 0.0001 );
FLOATS_EQUAL( expected.foo_bar, actual.foo_bar, 0.0001 );

and I column-select at the second or third "column", then indent and un-indent still operate at the beginning of the line, instead of at the left of the selection, like I expected.