beta 2 install not booting on chromebook

["john.tiger" <john.tigernassau@gmail.com>]

jessie beta 2 will not boot on chromebook in developer mode - it just 
flashes

jessie build from Jan 14 booted okay

same usb boots fine on macbook

wheezy usb boots fine

fedora 20 usb boots fine with mem=1048 (kernel 3.11)

fedora 21 usb does not boot either - flashes (kernel 3.17)

xubuntu 14.10 does not boot - flashes

so it seems like something with newer kernel - guess is mem setting but 
have tried numerous mem settings but no success

any ideas ?