after upgrade to 9.10, couldnt boot img-2.6.31-302-ec2

[u007]

Hi,

I've just upgraded from 9.04 to 9.10.
But after upgrade, i couldnt boot into both
- 2.6.31-302-ec2
- 2.6.31-14-generic-pae

error message when trying to boot:
- please boot the kernel first

But i could boot into:
- 2.6.31-14-generic

i tried checking
/boot/
and i found all the img and vmlinuz files in place...
not sure why i couldnt boot...
please help me...

[u007]

when i boot into:
- 2.6.31-14-generic-pae
no errors,
but when reach into xwindows, the screen keep flikering blank.. as like keep restarting xwindows, and it didnt stop attempting to set the resolution (i think)