I still find the concept of "2012" rather humorous although it does coincide with the solar cycle. Without getting to far into an "end of the world" discussion it does seem that the year 2012 is going to be an interesting year for solar activity.
SO far as i read, the reason for the 11 year cycle is not fully understood, which by the way if anyone has any link to info, post them i would love to read more. Anyways, what my impression seems to be is that major "cataclysmic" events in the sun cause major magnetic disturbances and changes. i.e solar flares and CMEs. The cause of this, my hypothesis, is a buildup of internal energy in the sun that gets released at the solar maximum causing the pole reversal and this loss of energy causes the sun to back into a buildup phase, the solar minimum and back to max, hence the cycle. Once again, only my little hypothesis on the subject.
I would compare it to a workout, you sprint for a while then rest to recoup your energy and so on and so forth.
as for the magnetar, i have no info on me about the reversal of a magnetic neutron star's poles.