Whew... this one is tough:

I don't think your DPS is the issue here, as you were able to get him down to about 76% before your entire party wiped. A significant problem that you're having is that your Paladin is getting ice blocked. You should be able to remove this via the skill Every Man For Himself (human racial), Divine Shield, or via AOE nuking. The other issue that I see is that your entire team is taking significant damage throughout all points in the encounter. May I ask why your priest is spec'd Shadow? I doubt that you'll be able to simply dps this fight without heals until you completely over level/gear the encounter. In an eventsuch as this, where your entire team will be taking large amounts of damage, you're going to want to at least try to aoe heal during it. Circle of Healing will provide a small boon, and you should be able to follow that up with the Prayer of Healing. Next, when the adds come into the room, you need to round them up... run up to them, drop a consecreation and use avengers shield (it should hit 3 of the 4 skeletons). The goal here is to control the agro so that you will be able to reduce the amount of AOE healing required. You're going to want to make sure you kill the skeletons in one spot as well, so that when they rez, you'll be able to repeat the consc + avengers shield strategy.

Good luck!