Well, I had same time to play with this again and unfortunately it still seems like a rocket science to me.
First, i can't even figure out, what is the difference between graphdefs.cgi and collection.modified.cgi. It seems as modifing graphdefs.cgi has no effect whatsoever... Yet they contain the same info..
When i try to delete section "if_errors => [ ... ]," from collection.modified.cgi, browser still displays broken image icon with location:
http://****/collectd-web/cgi-bin/collection.modified.cgi?action=show_graph;plugin=interface;type=if_errors;type_instance=eth0.1;host=*****;timespan=hour;start=19:30 Jul 8 2012;end=20:30 Jul 8 2012;
When i try to create a duplicate section of if_octets (hoping to tweak it, so it only shows upload) it wont show up.
Unless there is a documentation somewhere (which i doubt) or someone gives some direct hints for configs, i guess i'll be lost forever.
(there's no point of posting my code, since it's just the default one)
Thanks ;)