A lot of people with that version of Union's Toe Cap have issues with certain boots. What kind of boots do you wear?
I have a pair of Union Data's and a pair of Union Atlas's and have never had a problem. Rome 390's are awesome binders as well.
Maybe look into getting one of those style of toe caps.
I wear Salomon Syanpses which have a smooth round toe.... Union toe cap just doesn't work with it. Too bad cause outside the toe cap I like the Unions.