Under natty beta-2 this problem seems to have receded.
When I started the install, I set "nomodeset" on the boot parameters. The install ran fine, and booting the installed natty from the hard drive, I get no "striped pyjamas".
In maverick, a "nomodeset" on the boot parameters worked fine for booting, but I still got "striped pyjamas" on shutdown.
In natty, the shutdown experience is as expected, ie no "striped pyjamas".
Under natty beta-2 this problem seems to have receded.
When I started the install, I set "nomodeset" on the boot parameters. The install ran fine, and booting the installed natty from the hard drive, I get no "striped pyjamas".
In maverick, a "nomodeset" on the boot parameters worked fine for booting, but I still got "striped pyjamas" on shutdown.
In natty, the shutdown experience is as expected, ie no "striped pyjamas".