I was upgrading the hard drive in my MacBook Pro, so I started by making a Time Machine backup of my existing drive, which is running 10.6.2. After installing the new drive, I went to boot off my Snow Leopard disk. I couldn't find it, so I booted my machine from the original restore DVD (10.5), and did a 'Restore from Time Machine backup' using that installer. Three hours later, the machine rebooted from the new hard drive to an instant kernel panic.
I then found and used the 10.6 upgrade DVD to boot and do the restore again, and it worked flawlessly.
So, save yourself a matter of hours (plus a hefty amount of frustration!), and use the appropriate install DVD to restore your Time Machine backups!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20100407202624130