Blast from the Past progress ruined...

The game actually froze while I was in Batuu. That place is full of bugs. So I had no choice but to ctrl+alt+del out of there. By the time I retarted the game, my Blast from the Past progress had regressed back to "Research at the library" and now it wants me to build the time object AGAIN, even though it's in my inventory. It's not even buildable since I already used the time shard-- obviously. I fear this won't let me continue the event. :'( Help!