DMX problem with stinger laser

[kvm]

I have a problem with the stinger laser, i'm using the SL512ec box with 2004 software.

I don't know how to say it properly,
DMX is sending too fast? patterns of the laser aren't smooth (shaking?) missing some DMX information?

Stand alone mode of this laser works good, also working with a Liteputer or Botex scancontroler there is no problem.

Regards,
Martin.