Problem in boot of new kernel

Hi;
I have ubuntu 10.04 on VirtualBox and get kernel source 2.6.39-3 from kernel.org and compiled it.
After boot, I see this message:

The disk drive for /root is not ready yet or not present.
Continue to wait or press S to skip mounting or M for mount recovery.

How can I solve it?

Thanks.

How did you install 10.04 on the VBox virtual drive, and what commands specifically did you use to configure/build/install the new kernel.

I solved the problem by using mkinitramfs then update-grub2.

Thanks