There was an initial problem with a plot driver with the first Service Pack for AutoCAD 2004 which caused some problems in plot quality on HP devices. We worked non-stop to fix the problem the same day and will be releasing it to the web later today. We sincerely apologize for any inconvenience this may have caused. If you installed the first SP1, you will be able to install the new Service Pack over the already installed one.
Shaan Hurley (tired)