[PLUG] booting from sd card problem

[jayant ogale]

i am trying to boot ubantu from sd hc card on my laptop.
after the grub screen, ubantu splash screen comes but then it gets stuck here. when i press esc at this stage i get error message
can't open /dev/sr0 no medium found.
i tried to find any answers on google, but could not get solution.
if i do the same installation from usb pen drive, it boots very smoothly.
can someone tell me the solution?
thanks,
jayant