Hi TuanHa,
I posted
earlier.
Currently TuanHa (Special Edition) is not casting Obliterate. I'm not at my computer so haven't tested HB 707 (latest) but I had posted several dummy DPS logs with latest versions of CC and clean installs of HB.
My conclusion was that the CC was spending procs on Frost Strike instead of Obliterate, which is incorrect for 2H Frost PVE DK.
As per the Blood DK asking if 50-60k DPS @ i520 is normal: it depends on the fight and how much vengeance you are gaining. If you are off tanking a lot (and not gaining Vengeance) then your low DPS may be explained. Also we can all double DPS likewise in AOE etc etc. As long as you are staying alive then 60k DPS at 520 is fine. You should however be hitting 7.5% Hit (or just under) and the same 7.5% Expertise; at i520 you should have gear and gems to reach these goals, they may help improve your DPS. Also, I would say, that in i540 I can sometimes 'have' as low as 60k DPS... or as much as 360k DPS (zerg AOE etc). It is situational.
PS -the log -although it is very short -shows that offensive CDs such as Dancing Rune Weapon was not being activated in Burst Mode -amongst other CDs (potions, trinkets, profession perks -Engineering gloves etc) -are not being engaged by your current settings. You need to (1) address these in your settings or (2) let us know your setup -perhaps you prefer manual control over CDs yourself.