Ваша проблема связанна именно с транзакционностью плагинов CRM 2011. В SDK по этому поводу даже есть несколько строк:
Access to the Organization Service
To access the Microsoft Dynamics CRM organization service, it is required that plug-in code create an instance of the service through the
ServiceProvider.GetService method.
C#
Copy Code // Obtain the organization service reference. IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory)); IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);
The platform provides the correct Web service URLs and network credentials for you when you use this method. Instantiating your own Web service proxy is not supported as it will create deadlock and authentication issues.