can't boot off of volume made from 10.5 DMG
I'm trying to update an old iMac to 10.5. My original 10.5 disk doesn't work, but I have a .DMG that I made of it way back, and now I've used Disk Utility to make DVDs or thumbdrives as volumes of the .DMG. Problem is, none of my machines (older laptops, Mac Pros) can boot off the resulting volumes. I can see them and they look fine in Finder when plugged in, but when I run the updater that's on there, and it reboots to start installation, all I see is the gray apple and nothing past that. What am I missing - why can't it run the OS updater from a volume made from the DMG of the original install disk?