Timeout on plesk panel

[JeromeA]

Hi,

I upgraded a Plesk Linux 9.53 to 9.5.4
Since this, I have a timeout on accessing plesk panel

I have the top banner, with button "Continue" and after a few seconds a timeout of the navigator

With psa stop and start I have such messages
[Sat Mar 10 07:59:53 2012] [error] VirtualHost *:80 -- mixing * ports and nonports with a NameVirtualHost address is not supported, proceeding with undefi results
[Sat Mar 10 07:59:53 2012] [warn] NameVirtualHost *:80 has no VirtualHosts
[Sat Mar 10 07:59:55 2012] [error] VirtualHost *:80 -- mixing * ports and nonports with a NameVirtualHost address is not supported, proceeding with undefi results
[Sat Mar 10 07:59:55 2012] [warn] NameVirtualHost *:80 has no VirtualHosts

Some ideas, logs to view ?

Thanks