Using a shield and a bumper

Hi guys,

I want to ask for your advice on installing a shield to use at the same time as a bumper. I bought the Zagg IS (only shield I found) along with a black bumper, but I found it impossible to make them behave nicely.

No matter whether I put the shield first or the bumper first, the corners end up lifted and there's no way I can wiggle things around to fit.

I've seen some pictures of at least one user who managed to make it fit. What's the secret? Do you know some shield or case that could be particularly good for this type of combination?

Thanks!