"The phenomenon you describe, polar wandering, and the precession of the equinoxes are two totally unrelated and independent phenomena."

That's true.
I suppose one could say they are on a different axis.

And if Earth orbit was perfectly circular, the precession of the equinoxes would little affect upon earth climate. Earth's orbit is not a perfect circle. Right now summers in the Southern Hemisphere apparently receive more solar energy, than summers in Northern Hemisphere.
Earth orbit ranges from 146 to 152 million kilometers from the Sun.

There also a precession of Earth's orbit:

Wikipedia:
"It is generally understood that the gravitational pulls of the Sun and the Moon cause the precession of the equinoxes on Earth which operate on cycles of 23,000 and 19,000 years. The precession of the orbit of Earth is an important part of the astronomical theory of ice ages."
http://en.wikipedia.org/wiki/Precession