Stuck in shipping process

Hi,

I've upgrade the marketpress lite of my site to Marketpress Pro
Since then i'm stuck just after the shipping process : I'm entering my Shipping Information, press enter...and nothing happen (the page reload as it was, althought all the compulsory field habe been filled).

In marketpress lite, I was encountered no problem
Can you give me hint so I can resolve this problem ?

Thanks

PS : my url is http://effet-feng-shui.fr/boutique