Problems installing CCM 5.1

[PeTaKkI]

After finishing the preinstallation I got the following error message:

Cisco Unified CallManager 5.1.2.3000-2

Critical Error

The installation has encountered a unrecoverable
internal error. For further assistance report the
following information to your support provider.

Script
"/usr/local/cm/script/5.1.2.3000-2/cm-dbms-install
install PostInstall 5.1.2.3000-2 5.1.2.3000-2
/usr/local/cm/ /usr/local/cm/
/common/log/install/install.log" exited with errors (1)

The system will now halt.

When I reboot the system I have the following error:

"INSTALLATION FAILED - restart installation to recover from failure"

And then, if I reboot the system with the Install DVD or Recovery DVD it stops working (no keyboard input and no video output).

What can I do?

Thanks.