After developing a custom Web Service to be hosted in SharePoint (based on this HowTo article on MSDN ) and deploying it on a testing environment, I got some entries in the EventLog over there, stating: " Unable to connect publishing custom string handler for output caching. IIS Instance Id is 'xxxxxxxxx'...
Getting the ModalPopupExtender from the Ajax Control Toolkit to work (decently) in SharePoint was not exactly a walk in the park. With a default SharePoint installation, the modal popup is partly positioned 'outside' of the page (you only see the bottom right part of the popup in the top left...