Upgrade from 7.5.4 to 8.0 Broken HELP!!!

[MaRiOs]

I tried to update the Basic PAckage of Plesk to 8.0 from 7.5.4

I received an email with this failure:

===> Installing psa database
Trying to check psa database... Trying to find psa database...
Trying to connect with admin account... connected
Trying to check psa database version... version is 0754
DATABASE ERROR!!!
Previous product version is , but previous database
version is 0754. In most of cases it is result of
previous upgrade try failure. Please, restore previous version
from backup, and try again or contact technical support.

ERROR while trying to check database version
Check the error reason(see log file: /tmp/psa_8.0.0_CentOS_3.6_build80060425.18_installing.log), fix and try again

Aborting...

error: %post(psa-8.0.0-centos3.6.build80060425.18) scriptlet failed, exit status 1
Error while execute command rpm -U /root/psa/PSA_8.0.0/dist-rpm-CentOS-3.6-i386/base/psa-8.0.0-centos3.6.build80060425.18.i586.rpm
ERROR: error while executing RPM


Any help at all?
Plesk is not working. it shows a white page....