I have made the second beta available for version 4.2.0. I did mention this in a comment last night, but for the benefit of the testers I thought it might be a good idea to make an official post for this.
You can get the beta from here. The beta fixes a couple of bugs reported by Mark:
- There was an issue with incorrect sidebar counts coming up in the new Custom Post Type Archive.
- There was another problem with the “auto-arrange” for the Custom Layout template not working correctly.
Give it a try and let me know if things are fine.