We are delaying Alpha 39 for one week so that we can mop up some of the remaining bugs. A number of them accumulated over the last few release cycles, and since a significant number of users haven't been able to play, it wouldn't make much sense to make a release with the current state of the client. So far, we've already squashed a number of them, which you can see on our commit log. We've also restored color grading, which is nice.
If you're experiencing any bugs whatsoever over the last couple of releases, please post them here if you haven't done so already.