Unable to Change Publication Date

I upgraded to 2.8.5 this morning, with no apparent issues. However, when I try to change the publication date on an article, two things happen.

1. The date reverts to the current date when I hit [Save]
2. The article disappears from the front page when I hit refresh

When I hit [Save] a second time and refresh the front page, the article is there.

Since I am rebuilding a journal that was lost when the provider it was posted on went belly up, changing the dates backwards is critical. (I am only going back to 2006.)

Clues and hints to help me get back to work would be appreciated.

The site is boatswain.us