I can't seem to get past Day 4.
I know I've done pretty much everything that needed to be done as far as items/puzzle solving goes. Also, from what I remember the day should not take more than a few actions to complete (talk to Crash, etc.)
Anyone having the same issue?

I had the same issue on Day 4. Have you checked out the clock in Gran's house?

I was a prog on GK, but I really can't remember what day 4 was about. If you remind me, maybe I can help.

Having exactly the same problem, can't work out what I haven't done! Crash is dead [and his body is gone from the church], I have the tattoo sketch, Grace is doing research on the drummers.... What am I missing?

Called Wolfgang ?

I had the same problem. You have to call Wolfgang, yes, but that's not possible because Gabriel doesn't know who he is.
Obviously, there's a spoiler below.
Go to his grandmother's house, and get the photo and letter that are hidden inside the clock. Then talk to the grandmother and ask about the Ritters. Finally, go to Gabriel's studio and call Wolfgang.

I've myself had this problem the thing that I hadn't done in my case was using the sketch book on the grafity in the cemetery and then showing it to the fortune teller (the one that has a snake in a cage) that got my day finished.

I'm having the same problem, and I've been following a walkthru word by word. Step by step.

That was where i was stuck too, had forgotten to get a copy of the stupid marks, just spend 2 hours visiting every place and talking and showing everything to everyone :(

I was the same - that damned Voodooine! That finished my day, and I completed the game a couple of days ago, bloody fantastic game.

It is interesting to note that certain things don't have to be done in order ... I too was stuck on the Voodooine because I never was told to go see her. Thankfully, I finally read a FAQ and got back on my merry way.