Storing the OpenAccessContext instance in the session state could lead to wrong behavior if there are multiple requests to a page or custom handlers which are using the same session. This could lead to a situation when one request disposes the context before other request are finished doing their work, which will cause an exception. Problems could arise when the application is being used in a web farm.
Better approach is to store the context in the HttpContext.Items collection. You could find the sample application, shipped with the Product SDK
, helpful. They demonstrate how to handle the context.
Hope that helps.
the Telerik team