Suddenly (after I suppose some upgrades on Gentoo machine) news page and contact page (feedbackform module) in my cmsms 0.11.1 installation became blank (totally blank, no single character in source code). I tried to do something, upgraded cmsms to 0.11.2, upgraded feedbackform module, clear cache.. after several minutes all pages became blank

admin pages still works and if I enabled "site is down for maintenance" I can see this message.
After enabling debug in config.php I can't see any additional messages. But after enabling "site is down..." I can see debug message. I enabled logging in log4php.properties, but no results - log.txt doesn't contain any errors.
server configuration: apache 2.0.55, php 5.0.5, postgresql 8.0.4.
this is a "production" web page, please help.