Hello!
I am new here. I just downloaded the ML USB and copied it on my pendrive. However, upon first run, I got ApplePolicy KP which I fixed by deleting the respective Kext. After that, I got stuck at [PCi Configuration Begins] which I again fixed by using old IOPCIFamily.kext. After that, I got some USBF errors which I fixed using "USBBusFix=Yes"
But now, I am getting stucked here. I tried deleting all the ATI*.kext files and booting with "-f GraphicsEnabler=No" but still no success.