Are you able to log php errors?
PHP is encountering a fatal error most likely during wiki text parsing - while output buffering is in effect. If php errors are being logged, the log will explain what/where the error is.
Also, do you have any third party plugins? Can you disable those. If you aren't able to access the plugin manager (?do=admin may give you the admin menu), you can disable plugins by creating a file called "disabled" in the plugin directory. The file doesn't need to have any content, just to exist.
that is "you can disable plugins be creating a file called "disabled" in the directory of EACH plugin to be disabled."
Desactivation of all third party plugin hasn't solve the problem. Maybe I can log PHP error, but I don't know how...
PHP errors should be logged to your standard web server error log. They might be accessible through a web interface provided by your hoster or via FTP. Without any detailed errors we can't help you.
You might want to setup a completely new wiki on the same host in a different directory to make sure it isn't something broken in your installed version.
The problem seems to be solving itself ôÖ ...
Did you resolve the problem?
And if so were any changes/patches required to DokuWiki?
If not can this be closed?
No change were made to DokuWiki, the problem it solve itself... This task can be closed, sorry for the false report...
No need to apologise, its better to get the odd false report than have people worrying about whether or not something should be reported as a DW problem. Also there have been problems with PHP5 and PHP5.2, in particular due to changes to bundled libpcre and zip extension :)