Thanks for the link….I don’t know what your front page was before, but you may have to rebuild/redo what you did originally when you setup your front page. But I would still present your issue to the wordpress forums and see if others experienced a sudden loss of their front page.
I would also recommend checking out some form of backup plugin, or perhaps check out VaultPress (which I know is accessible via JetPack). It’s worth checking into that.