Config include_path of php on Linux

[rorqual]

Hello,
I have a problem with my Linux Server (apache,mysql,php)
I can't define the include_path in php.ini
There's only one php.ini to modify???
And the error message is :

failed to opening 'include_phplib/astro.inc' ...(include_path='')

also : in local (with windows 98) it's run properly
and the problem is because php dont know the include_path (the '' ...)

Thanks to send me the process to can run that!
Sebastien