Selecting 'Display Gallery on page load, user needs to click on the "home" button to show sidebar and content' and giving the post a password results in a broken portfolio item; In the portfolio the item appears as usual with a padlock. When entering that portfolio item the page is blank.
Caveat: If you've previously entered the password for that item (before choosing the 'Display Gallery on page load, user needs to click on the "home" button to show sidebar and content' setting) then the portfolio will work as expected.
Removing the password the portfolio item works as expected. Setting Instant Background Gallery back to 'Display Sidebar and content on page load, user needs to hide it manually' the portfolio item works as expected.
The code to hide the sidebar+content should really take place AFTER the password has been entered, i.e. when displaying the gallery. Not before.