Ok I tried to upgrade to 18.104.22.168 (not re-install 3.0.3) and reconfigure services
and also removed the
from my suphp.conf (as Falko told someone in a similar topic)
Not realy helped, but after I restarted the whole server, I had some good news.
Phpsysinfo worked for a few minutes (but now it only display "Loading Please wait" )
I will check the log files for more details.