after installing, everything normal, up to date.

when accessing the menu: Manage Sites, Models and Tools ..

Linking variables in php.ini
display_error = on
error_reporting

appears that:
Strict Standards: Non-static method Jms2Win :: matchSlaveSite () Should not be called statically in / srv/www/index/www25/administrator/defines.php on line 45

Strict Standards: Non-static method Jms2Win :: _getCurrentURL () Should not be called statically in / srv/www/index/www25/includes/multisites.php on line 6

Strict Standards: Non-static method Jms2Win :: _getHostInfo () Should not be called statically in / srv/www/index/www25/includes/multisites.php on line 6

If I turn off the error:
The screen goes blank

Joomla: 2.5.6

PHP INFO: www25.seduc.to.gov.br/phpinfo.php

ERROR LOG:
[Thu Jun 21 17:37:16 2012] [error] [client 200.163.65.111] PHP Strict Standards: Non-static method Jms2Win::matchSlaveSite() should not be called statically in /srv/www/www25/administrator/defines.php on line 45, referer: www25.seduc.to.gov.br/administrator/inde...mp;task=showSettings
[Thu Jun 21 17:37:16 2012] [error] [client 200.163.65.111] PHP Strict Standards: Non-static method Jms2Win::_getCurrentURL() should not be called statically in /srv/www/www25/includes/multisites.php on line 6, referer: www25.seduc.to.gov.br/administrator/inde...mp;task=showSettings
[Thu Jun 21 17:37:16 2012] [error] [client 200.163.65.111] PHP Strict Standards: Non-static method Jms2Win::_getHostInfo() should not be called statically in /srv/www/www25/includes/multisites.php on line 6, referer: www25.seduc.to.gov.br/administrator/inde...mp;task=showSettings
[Thu Jun 21 17:37:16 2012] [error] [client 200.163.65.111] PHP Strict Standards: Non-static method Jms2Win::matchSlaveSite() should not be called statically in /srv/www/www25/configuration.php on line 7, referer: www25.seduc.to.gov.br/administrator/inde...mp;task=showSettings
[Thu Jun 21 17:37:16 2012] [error] [client 200.163.65.111] PHP Strict Standards: Non-static method Jms2Win::_getCurrentURL() should not be called statically in /srv/www/www25/includes/multisites.php on line 6, referer: www25.seduc.to.gov.br/administrator/inde...mp;task=showSettings
[Thu Jun 21 17:37:16 2012] [error] [client 200.163.65.111] PHP Strict Standards: Non-static method Jms2Win::_getHostInfo() should not be called statically in /srv/www/www25/includes/multisites.php on line 6, referer: www25.seduc.to.gov.br/administrator/inde...mp;task=showSettings

The "Strict Standards" notification is not a fatal error and can be ignored.

You have to search for FATAL Error that may cause a blank screen.
Here I don't see any fatal error in your error log.

The strict notification can be ignore in the php.ini
I think you can use
error_reporting = E_ALL & ~E_NOTICE | E_STRICT

Ok So what might be happening?
Why is there white screen fatal error?

How can I find out?

what are the requirements of the extension?
I installed the Vertrigo locally, it worked ... more
on OpenSuse not ...

Joomla: 2.5.6

PHP INFO: www25.seduc.to.gov.br/phpinfo.php

A fatal error can also be due to the fact that you don't have access to a file.
Sometimes, this happen when the owner of the file is not correct.

Joomla 2.5.6 is OK and I also suppose that you are using at least PHP 5.2.4 or higher

Search for the fatal error.
Try also enable the joomla debug flage in the "configuration.php" file that will perhaps will give you additional info

Otherwise, try to add debuging trace into the joomla code to identify the place where joomla crash.

Hello distu. Were you able to solve this? I have the same symtoms with a clean installation of Joomla 2.5.6. Any help is highly appreciated. Thanks