Did you check the resistance of the Vivi Nova using the LavaTube's little window?
I had that happen to me once. The LavaTube told me the reistance was 4.9 ohms, and when I double checked with a multimeter, by golly, it was 4.9 ohms. Turning up the voltage to compensate for the higher resistance just resulted in a burnt taste. That head went into the "to be rebuilt" jar.
In the meantime, don't chuck the dead heads. Maybe you'll learn the craft of rebuilding Vivi heads. It really isn't hard, it just requires a fairly steady hand, a few simple tools and a hands-free magnifier.