I am working on capturing and deploying Lion images, and was thwarted from the get-go. It seems that the certificate bundled with apple packages from before March 23 have expired, and so when I attempted to create Netboot environment I found that it would error out.
This issue is probably resolvable by downloading a newer edition of the installer, but I found another workaround here:
"Expanding and reflattening a flat package has a side-effect of removing the package signing. the command-line installer tool will happily (at least as of this writing) install unsigned flat packages."
As the article suggest, this tool
can fix entire dmgs. I ran it on my Lion installer disk and was able to create my Netboot image :D