Are you using 1.9? If so, I believe this is a known issue. Journal assignment types are being phased out in favor of the assignment types (since the assignment type provides almost duplicate functionality). Somewhere around here there is a script that is supposed to convert them all, but I believe that's for an admin to do. I believe it still works bringing your grades over if you click the "Update Legacy Grades" option (it's something like that) on the bottom of the gradebook screen (I believe it's the button on the far right).
Good luck.
Good luck.