We had a problem recently with the Reactor burner specifically with the metal foam that dispurses the flame. The stove was transported with the burner inside the pot w/o the canister or any other item that filled the void in the pot. It looks like when the stove was transported by mules due to the vibration the metal foam in the burner was partlially destroyed and the middle piece fell into the burner. This drove the stove unusable. I did not have time to dissassemble the burner and see if the foam can be fixed.
Neither MSR or other online resources reports similar problem. Have you encountered such problems or it was the issue with this instance where the metal foam was not securely connected inside the burner.