I’m not sure when it happened, what firmware or hardware upgrade changed things but inexplicably and without warning I was unable to re-install OSX Snow Leopard on my 2010 Unibody Macbook Pro.
No matter what I tried, a standard retail Snow Leopard disk, the original disks that came with the Macbook Pro, the same result - a kernel error on startup.
I looked on-line, I tweeted and found more and more people with exactly the same problem. I even put the original hard drive back in (which I’d replaced with an SSD) and the original RAM. I reset PRAM etc and still a kernel panic.
I couldn’t re-install OSX and the result was an abomination; a Macbook Pro running only a bootcamp partition with Windows 7 running natively. Worse still, I could only run OSX in a VMware installation within Windows 7.
I was definitely going to hell.
But suddenly it has all changed. OSX Lion has been released (well the GM in my case) and after burning it to a disk and trying it, it installed successfully.
So if you have an iMac or Macbook that won’t install OSX Snow Leopard, try downloading to spare/friends machine and burning a disk - you may be pleasantly surprised.