Method not found: ‘System.Web.UI.IDataSource System.Web.UI.WebControls.DataBoundControl.get_DataSourceObject()’.
I got the error above when calling the IPostBackEventHandler.RaisePostBackEvent on a web page running on a server used for testing. Since it wasn’t occuring on any of the development machines then simple logic meant there had to be a difference in the assemblies residing on the server. In this case it was the version of the .Net Framework 3.5 as the server had not had SP 1 installed. Once the machine had been updated the problem was resolved.