Can't add DVDs

I can no longer add DVDs to my ‘Owned’ list. When I click on Add in the menu on the left I get the search box and can find items but once I have selected a DVD by ticking the box there doesn’t seem to be a way to add it to my list. At the bottom of the page there is a box headed “With selected create or add to custom list” but when I click on the "Add to list" button and go back to my main list I get a message saying “You did not choose a list or enter a new list name”. However, my existing list in not offered as an option in the menu on the Add page. Can anyone help?

Thanks.

I removed those because they are redundant now. You just need to click the links next to 'Mark as :' on each of the items.

Thanks Tom!