Coryjoe,
That is what Wick, and others meant by getting that surface flat. The lid doesn't jut up, the background falls away.
If the bed isn't flat(all the way to the end), then you'll have gaps somewhere.
Unfortunately, if you can't live with it, the only way to fix it is to start over. Flatten the background all the way to the end, and make a new lid.
Hope your day isn't wrecked.