I reviewed some of your guild's logs, and here's some feedback on your gameplay.
In no way do I intend this to be disrespectful, but you all around need to play the class better. Because the Stone Guard's mostly a tank and spank fight, I chose it to examine your gameplay. There, you maintained a Sacred Shield uptime of just 67% - you really should be 90%+ on that fight. Sacred Shield scales with Vengeance and those dogs hit you damn hard. It'll give you big absorbs. Maybe you need to use an addon like WeakAuras (which I use) to monitor this buff.
More worrisome is your Shield of the Righteous uptime, 25%. On that fight, which is mostly tank and spank and very short, your uptime should be at least 40%, if not 50%. You're having trouble mitigating damage, in short.
On each fight you use Divine Protection about once, and that's it. That spell's on a 1 minute CD and should be used pretty much whenever possible unless you're saving it for some reason (such as on Normal Elegon in preparation of Total Annihilation, unglyphed). There's a problem with WoL so you cannot see the usage of Guardian. Hopefully you're using that.
On Feng you got absolutely trucked, but it's not your fault. Your co-tank's supposed to taunt off at 2 stacks of Feng's debuffs, and yours...wasn't. I examined one section of the fight where you were taking massive damage, and lo and behold you had amassed 5 stacks of Lightning Lash. With all of those stacks, it's ticking for 100k a pop.
On the plus side, you seem to possess solid raid awareness. You stood in zero AoE on the Stone Guard.
tl;dr: take advantage of the active mitigation model by improving your SotR uptime, and work on maintaining Sacred Shield.
Edited by Trystero on 2/24/2013 10:07 PM PST