6th GPU not showing up and sgminer5 closes after black screen. ASRock H81

[zaqco]

ASRock H81 Pro BTC mobo
Windows 8.1 64bit [fresh install]
EVGA 1300 G2
6 x Gigabyte r9 270's [all of them]
AMD Catalyst 14.6 RC2 (I have tried 14.6 and 14.7 as well with same result)

Everything seems to work fine for the 5 GPUs while mining Cryptonote.
But when I attempt to run sgminer5 (all versions) a black window opens, and I get a quick glimpse of the

"Started sgminer 4.2.2
* using Jansson 2.6"

And then it closes.
I've tried older sgminer builds and I am getting far lower than expected (not even breaking 100 kh/s each)
And I've tried with running only a basic configuration to see if it will run and it still doesn't work.

Does anyone have any pointers?