The "System Config File /Library/Preferences/SystemConfiguration/com.apple.Boot.plist not found" error occures too when only using -s flag! what to do now? booting with -x -s?

ok -s -x doesnt work, same error...it seems now that this error occures everytime i want to boot (with or without boot flags!) - very stange!

when having the Beta 2 DVD in the Drive and booting with -x from hard drive it works, but after a few seconds a grey apple screen appears and a black windows which tells me i have to reboot my pc (without telling me why!)

PS: Ive bootet the Beta 2 DVD and with -s flag but theres no appleefi or Appleefi or AppleEfi.....maybe these are the DVD Kexts but how can u mount my disk1s2 drive when bootet with dvd to delete the kext?