Wintergrasp Quest Bug?

I'm playing on Onyxia and just completed all of the Wintergrasp quests. However, I have 3 quests that are marked as completed, but I’m unable to hand them in. The NPCs won’t let me interact with them, and there’s no question mark above their heads.

I’m playing Horde, and Horde currently controls the fortress, so I’m not sure why I still can’t turn these quests in. Has anyone experienced this before or know why this might be happening?

This has happened to me on Icecrown once before. Basically I held on to the completed quest and turned them into the the opposite vendors. So instead of at WG Castle, I turned mine in to the vendors that are at my factions starting spawn location. Worked for me.

The same happen to me in Icecrown.