Yeah, I don't think the rumble accepts the latest Robocode versions (220.127.116.11 and 18.104.22.168 only). I've updated the link for the superpack to my dropbox public folder.
As for the next step up in targeting, try pattern matching or guess factor targeting. If you're using the iterative circular predictor then pattern matching is easy, just swap out the velocity/deltaheading each iteration with a value from the history that you think started at a similar situation/pattern. For guess factors check out the GuessFactor Targeting Tutorial.