User blog comment:Fastolph Cottar/Terrain regen bug/@comment-68.226.70.27-20111222020128/@comment-4583259-20111222042019

If you haven't synced or backed up your iPhone (or iPad etc.) since that happened, and if you don't mind losing anything else you might have done on your phone since your last backup, then you could restore the iPhone from your latest backup with iTunes... I did that once and it worked.