I would be curious to hear what you're working on.
Is there any obvious trouble shooting steps I can take?
I did buy 2 DS1307s and crystals, so I could try the other one. Although as they were bought at the same time, they're most likely the same batch so if one was faulty the other one would probably be too.
As for running fast I haven't left my set up on long term yet so I'm not sure if I see the same issue. I'll try and remember to leave it running tonight and see what happens.