I guess that might be the problem or if some players keep huge farms etc.. But then I saw some blue birds spawn in promised land, but only like 2-3 at a time max.. still no pixies.. It's weird how I can't find anyone else has that issue.. Maybe other servers don't use default world generation and don't have Rainbow forests or smthing like that.. It's still odd do..

Important bug notice!
Use filing cabinets with care! They were the source of horrible lag we had last 2 days.. Seems they don't register the number of items correctly sometimes..
More on lag issue and these here - http://www.crazy-fools.co.uk/p/forum/forum_viewtopic.php?39602.last

also I have no problems with an advanced filing cabinet with enchanted books and the main problem might have been that some filing cabinets were connected to ME and seems only those were creating the issue..
so be careful and don't connect them to ME