As you know, the NCAA mandated the use of a new pole vault box collar/padding, beginning December 1st, 2013 for all D-I, D-II, and D-III schools (and it will be mandated for high schools beginning January 1st, 2015). 
Officials should be aware that in recent use of the new collar, there have been reports of the collar causing the pole to bounce back and knock into the bar even though the pole had been pushed back toward  the runway by an athlete.  This could be a problem and potentially a basis for a protest. 
This article is provided for your awareness of the potential for a  problem.  You’ll want your bar judges/flaggers to watch carefully for this and be prepared to make the appropriate call.