You are using the wrong crimp beads with the wrong crimp tool. You should consider using the #0 crimp bead. This is the correct size for the micro crimper. You could also use the #1 crimp tube. I know this can be confusing.
If you think about it..they way crimps work is they hold two wires together. When you use a crimp to station beads you are only using one strand of wire. This means that there is more space inside the crimp that is not be taken up by wire. The crimp will not really perform properly and this is why they are breaking.
Consider using the #0 crimp beads and just gently pressing it flat with chain nose pliers instead of using the crimp tool for this application. It will hardly take any effort to get a solid connection and since the #0 crimp bead is so small it will not take away from the look of the design.
Thanks! I had specifically asked the salesperson when I bought my supplies, but it is confusing, with all the combination's available.I got some #0 crimps and it worked just fine.