I wrote two weeks ago about a couple of errors in the November ranking.
As EngelRS4 announced in this comment, FIFA have changed the October 2011 FIFA ranking, by computing the ranking without two matches that have lost "A" match status: Korea Republic - Poland 2 - 2 and Ethiopia - Sudan 1 - 2, both played in October 2011. That's a new approach, as FIFA usually didn't recompute the rankings when a match lost "A" status.
What teams were affected by this change?
Korea Republic climb two places from 31st to 29th - tied with Egypt.
Colombia drop one place from 30th to 31st.
Ethiopia climb from 136th to 135th, swapping places with Kenya.