Objectives *sometimes* not spawning

I've got two story arcs that have occasional issues with objectives (bosses and destructible objects) not spawning. I don't know what to do about this, I talked to pohsyb about it back in Issue 14 beta, and he said he was trying to nail it down, but I haven't heard any mention of it since.

The first arc is Win the Past, Own the Future (Arc ID #1429), for which sometimes one of the boss objectives in the first mission won't spawn (note that there also is a spawn on a catwalk above the open area that lots of people miss-- I'm not talking about that spawn). Also, sometimes one of the boss spawns in the final mission won't spawn. These problems have existed since Issue 14 beta, and despite map changes and objective type changes, they have persisted.

The second arc, is Death for Dollars! (Arc ID#1050). In this arc, sometimes people report the final boss of the first mission (the Super Grunt) not spawning, and sometimes they report a destructible object in the second mission (the Special Bonus Prize) not spawning. When I run through the arc, sometimes they all spawn fine, and sometimes they don't. It isn't consistent. Note that I never received reports of problems with this arc until Issue 15 went live.

Has anyone else had intermittent issues with objectives not spawning like this? Have you found any way to fix them?

One of the feedbacks I got on my arc said that one of my destructable objects didn't spawn and they had to restart.

I have since changed object type but I have no idea if this fixed it or if it just hasn't been noticed.

One other thing that I did noticed (and part of the reason I changed object type twice) was because I was able to target the object but couldn't actually fire of a power at it. This happened to my controller (blind), blaster (ranged single target attack the name of which I can't remember this early) and my scrapper (ripper). If I ran around the object a bit, eventually I could hit it but it was a really annoying problem. The object was on a flat surface with nothing impeding line of sight, so I have no idea what the problem is/was.

I'm constantly tweaking it so I might have another look at object types in the near future.

But no, you aren't the only one who has had this problem.*

Can it be that there were no free spawnpoints for what didnt spawn?

I had the impression that was the problem when it happened to me, as the MA doesnt seem to calculate all that precisely all that MIGHT happen (and I dont blame it for that). With me it seemed my boss didnt spawn when I didnt defeat anything on the way to him but spawned an ambush, so I thought maybe the system thinks all spawn points are occupied.
(and no, he didnt just spwan somewhere else on the map then, believe me, it was a really small and linear map.)
When I defeated things on the way to the boss it didnt happen. No idea if that WAS the problem though.

Yeah, I've checked all of the allowed spawn points and such. I checked them again tonight, to see if maybe the maps have changed without my knowledge. I'm still not going over the limits (that is, unless "any" doesn't actually mean "any", but that only applies to one of the two missions).