problem with virtuemart

Hello everyone,

I installed and I use virtuemart memovie.
When I want to place an order, command validation beyond me SomePage white.
Unable to continue.
By cons when I change the template and I took the basic template of joomla I can finish my order perfectly.

I use Joomla 1.5.18 and Virtuemart * Inventory 1.1.5.

Can you help me on this problem please.
At your disposal for further information if necessary.
Thank you.