You are likely running into a WCF/HTTP request size or timeout limit, which you can adjust in the .NET configuration files.
On the client, you should add a ServiceReferences.ClientConfig to the Silverlight project to provide configuration info, and on the server, modify the serviceModel settings in the web.config.
In the Learning Resources, there is a sample ClientConfig in Deployment -> Code Snippets -> Sample Files for a Silverlight App deployment.
In
Deployment -> Code Snippets -> Sample Configuration Files for an N-Tier Deployment there are some server-side samples. See “Server app.config.default” for an example including timeouts (unfortunately there’s no web.config sample in this folder, but the serviceModel stuff is the same). Make sure to set both the sendTimeout and receiveTimeout on the client and the server.
There’s also another setting in system.web for large packet sizes:
<system.web>
<!-- HTTP RUNTIME CUSTOMIZATION
To customize the HTTP runtime, esp. when sending large amounts of data, uncomment this element
and set the appropriate attributes. See
http://support.softartisans.com/kbview_825.aspx and
http://msdn.microsoft.com/en-us/library/e1f13641.aspx for more information.
<httpRuntime maxRequestLength="102400"/>
-->
</system.web>
I would recommend using the WCF Service Configuration Editor (available from the Tools menu in Visual Studio) to edit the ServiceModel stuff.
You can also look up WCF system.serviceModel on the web for additional help.
Edited by ting - 23-Jun-2010 at 6:39pm