PLESK SUPPORT FIXED IT.....
Hello,
I found that upgrade failed:
[root@www ~]# rpm -q psa
psa-8.0.1-rhel4.build80060613.20
psa-8.1.0-rhel4.build81061129.22
I upgraded Plesk manually:
[root@www base]# rpm -Uvh --force psa-8.1.0-rhel4.build81061129.22.i586.rpm
Preparing... ########################################### [100%]
Trying to define super-server internet daemon type... xinetd
Trying to check if xinetd daemon is running... done
Congratulations!
All stages of the upgrade were successful.
Plesk is now running on your system.
To complete the system configuration process, please proceed to URL:
https://monkeydesignhouse.com:8443/ or
https://88.208.210.152:8443/
Use 'admin' and '<YOUR ADMIN PASSWORD>' as login name and password.
After that I've got it worked.
I rebuilt apache configuration:
[root@www base]# /usr/local/psa/admin/sbin/websrvmng -a -v
[root@www base]# /etc/init.d/httpd restart
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
Now all should work fine.