Wizards for Vaadin - Centering issue

Hi all,

I'm relatively new to the Vaadin forum and Vaadin community in general.
I've been working on a university project the last few months, and have used Vaadin for it's front-end.
In our UI, we make use of of the "Wizards for Vaadin"-addon, which in general works very well.

The issue I'm having is that, when the sizes of the different wizard step windows change, the wizard window in it's whole doesn't stay centered. It tends to scoot around.

Does anyone on here know of a workaround? I've never succeeded in getting it to work: I tried calling center on windows resizes, on step changes, .... None if this seems to work.

Thanks in advance,
Ruud