Install Bootmii as Boot2 if possible. Otherwise, try IOS. Install the new HBC and DVDx, too.
After installing Bootmii/Boot2, the Bootmii menu appears on boot. To get around this, use Bootmii Configuration Editor (I think it's on Homebrew Browser) to change some of the settings e.g. autoboot to System Menu, timeout 5 seconds. These settings will make it so that 5 seconds after the menu shows up, the System Menu loads. Any changes in the configuration are non-permanent and reversable.