I want to install 10.6.3 into a partition on my main 10.8.3 HD.
I created the USB drive like I have many times using the same thumb drive with different flavours of OS X in Disk Utility and System prefs even recognises it as a bootable drive in the Start Up Disk pane.
Boots into the grey screen with Logo but it just stays there and there is no flickering LED activity on the thumb drive.
It worked with Lion / Mountain Lion.
I created the USB drive like I have many times using the same thumb drive with different flavours of OS X in Disk Utility and System prefs even recognises it as a bootable drive in the Start Up Disk pane.
Boots into the grey screen with Logo but it just stays there and there is no flickering LED activity on the thumb drive.
It worked with Lion / Mountain Lion.