first page is blank screen after installation

[m_pahlevanzadeh]

Dear all,
Unfortunetly, after installation of cacti from official guide, i can't see http://x.x.x.x/cacti
My distro is RHEL 5.
I have php5
net-snmp
apache2
mysel-server 5
& everything that is needed.

Even when i `cat log/cacti.log` , i see it empty.

Please guide me ....

[gandalf]

Does this appear on the very first login?
What does httpd's error_log say?
Reinhard