There are three issues with the Job Service I have seen frequently. First, if you see an “Http response error” in the event viewer the Admin user is not associated with the Webdll user. Open the Administrator and select the Admin user, turn on windows authentication, and then browse to the Webdll user.
Secondly, the Job Service runs reports. If the reports stall and never finish it is most likely due to the shared directory for Documents. Please look in the Administrator at the Library and Documents folders, and share them. The next common issue is the Job service running under the local admin account. Please change the Job service to run under the Webdll user account (the same account running the Application Pools).