Some mobs in ToV appear to be immune to the blur effect, is that what you are experiencing? Your post is rather vague.
I was in CotF, running a mission in ETWK (forgot which one). I was in the caves, and tried to use Smokeveil to pull. I dropped the Smokeveil, and it mezzed the mobs, but when I tried to pull a single out, they all "woke up" and attacked. I tried this a few times in other lower level zones (ones where I used to use the lower level Smoke bombs), and the same thing happened. The mobs mez, but when I go to single pull one out of the pack, they all "wake up" and attack. (I just came back from a few months hiatus, so just noticed this. If there is already a discussion on this, I apologize for the duplicity.)
I've also noticed something weird with the trap recently. I've had it not blur things that I know can be blurred in Rygorr and ToFS. There's something strange going on with aggro I think.
No issues so far , I haven't had a problem with smokeveil in Mines or ToFS, now Kael is a different story the giants laugh at smokeveil, wolves too. I've also noticed Escape doesn't work either in Kael (then again it was really late and i was tired) but I know i hit Escape and maybe their agro range is much larger but the dog reagroed me.
When you drop smokeveil, what do you use to pull with? I have always used Shadow-Hunter's Dagger, but perhaps I should be using something else.
I use Vigorous Dagger Throw (yes, the very first one from UF) - tho I haven't used Smokeveil much this expansion. I *did* notice something wonky with my escape, tho. I escaped in ToFS, dropping a skel and an armor. Got the evaders fade invis thing, whatever. They reaggroed me like, 10s later and beat me to death. I was less than amused. It happened again later. No idea what the issue is, since I've used it other places and it worked npnp.
I haven't had any issues with mobs I know this works on. I target the mob I want to pull in the group, then squirt out a smoke, back up. Then I use Staff of Viral Flux to pull mob I have targeted. When they hit the smoke, I pull the one out of the group with the dagger throw ability and he comes out of the mezzed group. Easy peasy.
I have not experienced this in game. Tried it out several times last night. To me it's working right. If your throwing at a caster run away or around a corner before it cast, or it'll stand there and reaggro everything as it cast.
The buff we get seems to break off we get hit by spells. So if there's a caster in the group our hide /sneak AA that makes it not break doesn't help us.
Ok, I see here that you do this differently than I have ever done. I have usually gone in, dropped the bomb, then pulled out of the mezzed crowd, whereas you are pulling to the bomb, then separating. Could be that I need to change my tactic. I usually do this with caster mobs. The problem I was having is that when I dropped the bomb in the middle of a group of mobs I would then hit one with Shadow-Hunter's Dagger and it would break mez on all the mobs. I will have to experiment more with this and see what it does. I do know that it is LoS, and that if you bomb an area where a mob is out of LoS it can pull that mob out because of chain aggro. I will give that a try.