Grub demage my boot loader

[Jindřich Káňa]

Hello, I am new in this mailing list and my english is very poor :)

I have installed FBSD 8.0 on my first SATA disk. I downloaded Ubuntu  
9.10 CD and boot into the Ubuntu installation. After booting proces a  
choose 4GB USB memory for installation as hard drive. There is  
option: delete and use whole disk for Ubuntu. After installation and  
reboot I have error message - error: no such disk and something like  
CLI (grub rescue).

A tried steps by this link: http://lists.freebsd.org/pipermail/ 
freebsd-questions/2004-May/047549.html but without luck - there is  
still Grub!

Also I tried step from this page: https://help.ubuntu.com/community/ 
Grub2 but advices/commands (like boot, normal or dump, etc) doesn't  
work!

Is there any way to solve my issue?

Thank you very much for any advices!
Jindra