Centroid of point appearing outside of point when snapping  (result: incorrect snap)

Discussion created by katherinehayman on Aug 8, 2013
I am snapping points to polygon edges, which should be a simple task.  However, when I drag the point over the polygon edge, it appears to snap to the edge but then, once released, doesn't actually snap to the edge and shows the centroid outside of the point.  Usually but not always, deselecting and then reselecting the point temporarily solves the problem.  This is not a problem related to multiple points or layers being selected- only one feature in the entire map was selected when the snapshot was taken.  Snapping was set to Point and Edge. 


This only occurs during manual snapping- the snapping tool does not seem to be affected.  It doesn't happen every single time, but it happens enough that it is very disruptive.  The problem can be circumvented by editing the vertices of a point and moving the vertex to the edge, but with stacks of multiple points snapped together this is not viable. 

Any assistance or related experience is welcome.