I can see the commonality in that they are all poisons, and if they are coded based off of a common poison, then the poisoning is broken. Going back to the 1.8 release, everyone found that cave spiders poisoned in singleplayer, but in SMP the player would simply have their hearts turned diseased yellow, and nothing more.
Similarly, no AoEs work and they have a big factor in common; they're AoEs. In general, AoEs spells work on Mobs but not players. Why? The only cause I can guess is that players are given unique IDs that Mobs are not, and that the AoE only hits one kind of ID at a time. But if this is so (which it seemed to be with cleave) then only zombies in a group of mixed mobs may be hurt from pulse, whereas another test will show only skeletons in the same mixed group. This I know from experience (cleave withstanding) is not true, as I've seen Icy Aura hit mobs indiscriminately same as with pulse.
Also, I was being about as descriptive as possible, the skills constantly miss, poisons don't do poison damage, and AoEs don't do damage to multiple players. There is nothing more I can say based on those (which are the only) observations I can make.