Tachyons observed in simulations

There seems to be particles that have a velocity higher than the speed of light. The way to check this is adding to Cascade.inl at line 208 the following code:

    if (particle.getVelocity().getNorm()>1.1*299792458._m/1_s){
      std::cout << particle.getPID() << " Tachyon!!   beta = " << particle.getVelocity().getNorm()/(299792458._m/1_s) << std::endl;
      std::cout << "Mass squared in GeV: " << (square(particle.getEnergy())-square(particle.getMomentum().getNorm()))/1_GeV/1_GeV << std::endl;
    }

A sample of the output that one gets is:

photon Tachyon!!   beta = 1.767
Mass squared in GeV: -0.001
e- Tachyon!!   beta = 2.253
Mass squared in GeV: -0.001
e- Tachyon!!   beta = 2.297
Mass squared in GeV: -0.001
e- Tachyon!!   beta = 3.255
Mass squared in GeV: -0.004

The simulation was done with the testing-branch-May23 with the corsika.cpp example with the following input: ../bin/corsika -A 1 -Z 1 -E 1000000 --emcut 0.01 --hadcut 0.01 --mucut 0.01 -f test --emthin 1e-06 --max-weight 100 -s 2