While it mentions both shadows and fire spells the following thread is not about how they respond to each other. Rather it is about how players respond to all incorporeal creatures and why. It's also about what can be done about that to improve the game. It has nothing to do with the changes from monday's patch.
Look guys, and by guys I mean Devs, here's the deal. The reason people use Wall of Fire on your undead is that they suck. We mostly use it on the incorporeal undead and here's why.
You can't cast spells on them. They phase out all the time and you waste your SPs on "not a valid target." I even tried casting some spells now that I have quicken. It still doesn't work. You either spam them, wasting about 75% of them and landing the rest, which is not good for your SPs, or you just give up on spells other than persistent AoE spells.
This problem is almost equally true for everyone else. Melee characters' best option is to stand around swinging at thin air hoping to catch them when they phase back in. Ranged characters have it easiest, relatively speaking, but given the problems inherent in Ranged attacks in DDO, that's not saying much. They also suffer from some of the same issues as everyone else, what with the things disappearing right out from under your arrows.
Wall of Fire on the other hand hits them every time they phase in. It's like you custom designed it for these super-annoying crappy-ass mobs. But then you get upset that people are just Wall of Fire-ing everything. But the problem, honestly, isn't Wall of Fire. It's the phasing.
People would still Wall of Fire if they didn't phase, but we wouldn't layer them and drag them all over. We also wouldn't be quite as upset when you just made things immune to Wall of Fire because there would be other valid, useful, reasonable tactics to use against them.
I know you've justified this phasing before by saying the things are intangibly sinking into the floor, and I've fired back with several reasons why your justification is flawed. The biggest reason is the Ready action, which allows PCs to essentially hold their actions until the target appears and fire at will. This means your sink-into-the-floor tactic really just delays everyone's assault on you in D&D. It's nothing like the "I'm going to waste all your SPs and make you just stand around looking like a dumb ass" tactic that it is in DDO. Thus, quite clearly, there's a problem with your implementation of this tactic.
And all of this is on top of the already existing difficulties of incorporeal undead. It's bad enough that no one can crit them, or sneak attack them and that we all have to use our ghost touch weapons, which are generally sub par (or suffer a 50% miss chance). And there's almost no chance to hit them with an instant death effect and stop it all before it starts, since all the spells don't work and the chances of finding a ghost-touch disrupting weapon is slim-to-none. Then you add this "feature" that just wastes time, resources and patience without actually adding anything to the game. It's not fun.
Since there's pretty much no way to implement "ready an action" for a real-time game like DDO, it's time to just give up the ghost (pun intended) and get rid of the phasing that incorporeal creatures do. I'll even let you keep it on Ogre Magi and Phase Spiders (since both of them have abilities that are much closer to their implementation), but the incorporeal undead have to stop. I don't lightly ask you to do things that would just benefit the players. And I'd never do it for no reason at all. But this has always been a problem and it's just getting worse.
So here's the deal. Get rid of the phasing and I guarantee you that the majority of the complaints about how LotD sucks will stop. It's a tactic that's not in keeping with the D&D rules. It's a tactic that's extremely unpleasant for the players (and not in a "Aw shucks, you got me" kind of way). And it's a tactic that needs to go.