[Typo3] Installation problem: suphp error: index.php is writable by others?

[Bernhard Wenzel]

Hi,

I can not get typo3-3.8.0 working on my server.

I followed the installation description and now I'm stuck.

When I hit the typo3 website, I get "Error 500 Premature end of script 
headers: index.php"

The apache log says:
-------------------
Premature end of script headers: index.php
Error in suphp.c on line 247: Inappropriate permissions set on script

And suPhp log says:
------------------
[error] Script (/...link to my typo3 installation .../index.php) is 
writeable by others

The index.php as the link index.php -> tslib/index_ts.php. I can not 
change rights here. I don't know how to deal with suPhp, I'm a php newbie.

Any help is greatly appreciated!

Regards