User blog comment:Stormforce702/VERY Strange Bug/@comment-1426547-20120315090121

are you sure you didn't accidentally deleted them in your 'my documents' folder? Thats where your savegames and worlds are stored. In my case its stored at

C:\Users\Michel\Documents\My Games\Terraria\Players C:\Users\Michel\Documents\My Games\Terraria\Worlds

So you may want to check inside your documents. If the files are there, there is something wrong with terraria. If they are NOT there, chances are your files have been deleted.