Pole vector constrain causes poly object to flip

[kgg333]

I am using the book Maya Character Creation--and following its rigging chapter. When i put the control icon arrows in front of the knees--and the elbow control icons behind the elbows as it instructs-
then select an arrow and its corresponding ik handle chain--and go to pole vector constrain--the polygon bones along the ik handle flip in a weird direction. To get it back to a normal position I have to move the arrow all over the place..or put the arrow in an original position not recommended in the book and then do the pole vector operation. Then it doesnt flip.
Can anyone explain why it flips and how I can correct it without having to alter the arrows?

[gmask]

I suppose it flips because of some slight variance in how you built it but moving the arrows around to correct for this after constraining is not a problem and can be expected occasionally.