Warlock: No single DoT is benefiting from spelldamage

cabbie (are you btw?) can you do me a favour?

since you are running vanilla, go download Theorycraft, ingame press /tc
window that pops up has three tabs, go to middle one, look to your right, has a couple of boxes in regards to spell coefficients. Activate everything related and come back with some numbers?

just plain curiosity, assuming you'd indulge me that is :s

Would like to add a picture, but it seems not to be possible at the momemt.
So I will write down, what TC spit out on my tooltip for corruption:

Base + Dam: 301
+ Dam Coefficient: 100.0%
+ Dam Efficiency: 19,4%
Final +Dam: 301
DPM: 3.61

It's doing 111 dmg per tick naked.
And doing 124 dmg per tick with 301 +spelldamage

Curse of Agony is not affected by any spelldmg. It starts to tick with 43 both, naked and 301 +spelldmg

I am 100000000000% clueless in scripts, C++, minus, divination, be it entrails or fish guts and anything programming related, but i think we just found out what the problem is not! :)

What you see in what you are posting is:

1) the damage ---before--- ANY coefficients are taken into consideration+applied, it being 310
2) the coefficient to be applied in said value, in your case again 100%
3) the end result which should have been a value of 310 to determine your damage output for said spell.

Looks ok..

edit: Did the math wrong in original post, ammended it! lol

Look at mine:

DPS from +dam: 33,9 (39,4%)
Average Hit: 2066
Multipliers:
Base + Dam: 740
+Dam Coefficient: 110%
Final +Dam: 814

ie that 100% in your case or 110 in mine is not an additive, but a multiplicative