Weapon unlocks disapearing?

[Subion]

I beat the first level with Silent Assassin rank and got a message saying I unlocked the Silverballers SD. I started the second level and had them in my inventory and quit the level mid play. I started back up and now my Silverballers are gone from the game and my weapon selection.


EDIT:
If you go back to dashboard and start agin it seems to fix the bug.