From Beau Hollis (the "Prepar3D Rendering Lead") at Lockheed Martin in response to a "black screen" problem;
Quote from Beau on January 17, 2014, 18:26
We have fixed all the black screen bugs we could reproduce as well as issues with some settings not saving out. Can't say for sure, but I think this will be resolved by the next patch. Does clearing the local app data help? If not please post the working and broken config file contents as that may help us fund the issue.
Rather than a lot of small incremental patches, it looks like LM prefers a LARGE incremental patche.