Hi Christopher,

Currently there is a problem on some macs when the screen goes into sleep mode.

We use the QuickTime libraries to do the final stage of conversion and these can fail when the screen goes into sleep mode.

If you go into System Preferences, Energy Saver settings and turn off the "Display Sleep" option it should fix this problem.

We should have this fixed when we release VoltaicHD 2.0 next month.

Cheers,
Craig.