EDIT: IGNORE THIS POST - The the game connected to GOG for me shortly after I posted this.

original message:
Anybody with SR4 Game of the Century on Steam able to connect it here on GOG? It is not identifying when I try to connect. It did connect SR3 for me without problem, but not SR4. I'm guessing it's having trouble identifying all the DLC.

I'm glad you got it worked out otherwise, but the API doesn't distinguish between any owned DLC (which is why the one piece of DLC for Gat Out of Hell isn't on Connect).