I recently finished the quest "The Man Who Waits", but I did so without speaking to Gram and the quest is now incomplete and just stuck in my journal.

I've had the same problem.  Any work-arounds?

I had the same problem, as well. Since it was a main quest I didn't want to get stuck several more hours into the game by not being able to resolve it so my workaround was to reload from a previous game. Not the best workaround though, as I lost some hours since my last save was quite old...

oh crap, I think I hit this too. I assumed that something (event?) was supposed to happen a later time to close down the quest for me. Crap. I'm like five hours on.