BDC related data item list error

Question

I have a business data item list and two related item list on a page. Whenever the page is loaded I get an error could not connect to <instance name>. see error log for details. But once I select an item from the data item list both the related item list populates with the data. The only time i see those error are when the page get loaded. When I had a look at my log files I see the following error. Can any body help me how to resolve?


07/01/2009 10:39:46.59  w3wp.exe (0x10D0)                        0x1C58 SharePoint Portal Server       Business Data                  8u7q Exception  System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.SharePoint.Portal.WebControls.BusinessDataWebPart.GetConnectionItemsNeededMessage()     at Microsoft.SharePoint.Portal.WebControls.BusinessDataAssociationWebPart.get_ReasonForDisablingDataSource()     at Microsoft.SharePoint.Portal.WebControls.BusinessDataListWebPart.OnPreRender(EventArgs e)