As described in http://www.yafaray.org/community/forum/viewtopic.php?p=32005#p32005  http://www.yafaray.org/community/forum/viewtopic.php?p=32014#p32014 and http://www.yafaray.org/community/forum/viewtopic.php?p=32016#p32016  there are several Blender functions with Instances, Particles and Children that are not implemented in YafaRay.

I've checked the example scenes provided with older YafaRay versions back to v0.1.99-experimental and they all have the same problems so it looks like those Blender functions have not been implemented/supported in YafaRay yet.

It would be good that YafaRay could support these functions correctly.