If

Console -> Cacti Settings -> Data Storage -> Structured RRD Path

is selected, the folder named after the ID of the device is created immediately (unlike previous cacti version, where it was created by the poller) but with a wrong user owner and attributes, and it is impossible for the poller to write into such folder (apache:apache is the owner)

This does not happend if Structured RRD Path is not selected, RRD files are created by the poller correctly.

Workaround:
1 ) add the poller user (i.e cactiuser) to the apache group
[root@cactiM cacti]# groups cactiuser
cactiuser : cactiuser apache

[root@cactiM cacti]# groups apache
apache : apache

2. /var/www/html/cacti is owned by cactiuser:apache for all folders and files (recursively). Set sticky bit to rra folder:
   chown -R cactiuser.apache /var/www/html/cacti/rra/
   chmod -R 775 /var/www/html/cacti/rra/
   chmod g+s /var/www/html/cacti/rra/

Reason: chown can only be executed by SuperUser(root), so the if statement in lib/rrd.php fails.

This is also noted in the poller_maintenance.php file:
// NOTE: chown/chgrp fails for non-root users, checking their
// result is therefore irrevelevant

See this post in the forum for screenshots and details: http://forums.cacti.net/viewtopic.php?f=21&t=56998