Alright, this is primarily about the great northern wall mission, but it probably applies in other places too.
When you open the wreckage for Kinn Testebrie's armor, its assigned to a random person in the party, like any other container. If you have henchmen though, sometimes apparently the drop will get assigned to them, and thus you will not recieve a quest item necessary for the bonus. This wouldn't bug me too much, as its very early and very easy, but I was on with necro one night and didn't really feel like getting a group together, hadn't done the bonus so I went for the 1000xp, and I had to re-do the mission 3 times before I could get all the armor. It didn't make for an enjoyable experience one way or the other. That definitely sounds like a bug to me, don't know if anyone else has noticed or been annoyed by it, but supposedly ANet reads this stuff, so here it is.
Just a little bug what's bugging me...
Rig Jarlsson
Rayea
dosent a drop un-register after a while, or is that just for players and not if it gets named to an henchie?
Thomasuwoo
Hechies just "eat the loot" It never drops. Type out a bug report out area net with the /bug command. I'm sure they'd like to know about that.
Teutonic_bladehand
this has happened to me once as well...I tried it with a group full of *Beeps* and they didnt listen to me at all..so I left and I decided just to run though it really quick with a few hench...I found 3 pieces of armor and the fourth was no where to be found...I've done this bonus plenty of times so I didnt miss any places....trust me, I looked many times over. 
Basically...I think that the four pieces only drop when the group are real people...this has once again happened to me on the "feed joe" quest in the shiverpeaks. I did it with hench and not enough roots dropped, however, when I did it with real people, every piece dropped as it was supposed to...mabey this is just a henchie glitch? who knows....I wish they would change it, and also not let hench suck gold from the "shared" when you pick it up 
Basically...I think that the four pieces only drop when the group are real people...this has once again happened to me on the "feed joe" quest in the shiverpeaks. I did it with hench and not enough roots dropped, however, when I did it with real people, every piece dropped as it was supposed to...mabey this is just a henchie glitch? who knows....I wish they would change it, and also not let hench suck gold from the "shared" when you pick it up
Forboding Angel
btw quick note.
After release /bug doesn't work anymore (at least not officially).
After release /bug doesn't work anymore (at least not officially).