cannot install Dynamics CRM List Webpart

Hi,

I'm trying to install the CRM 2011 RTM bits. I have a problem with the CRM list Webpart. The solution is deployed and activated in Sharepoint, but when I try to put the webpart on a page, I obtain the following error : "Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trus app domain: An unexpected error has occurred."

The Sharepoint 2010 user code host service is started, and my server is not a DC.

Do you have any clue ?

Thanks,

Fabien