When setting a closing date and password in QuickBooks and checking the box for "Exclude estimates, sales orders and purchase orders from closing date restrictions dated on or before the closing date" it stays checked as long as the same user is logged in in Single-User Mode. Once the user logs out, or another user is logged in the box unchecks itself.
This issue has been resolved in the latest release for QuickBooks 2014.
Update to the latest release:
Go to the Update to the Latest Release web page.
IMPORTANT: Make sure your product is selected. If not, click the Change link and select your QuickBooks product.
Select and follow the instructions for one of the update options: