i wasted 2 dvds trying to burn the lion installer as per the instructions floating around the web. the burn was successful in both cases, verified properly, mounted fine, and even showed up as a boot option when holding down alt during reboot. but every time you actually did boot from it, it would hang on the apple logo and the drive would read endlessly. did it on both my computers.
so i ended up creating another partition on my hd and restored the disk to that. booted into it fine and the installation is now humming along.
(for the record, i'm jumping through these hoops to avoid upgrading my SL partition till i know lion will do what i need for work; so i'm creating a separate partition and freshly installing it there for the time being)