I ran into the all cores online issue that others who tried to go from DSB's cubed 2.4.2 kernel to DSB's stock write kernel have had.
I used Flash GUI to flash the Return to Stock boot.img, booted into recovery (TWRP 22.214.171.124beta touch recovery) and then flashed the Return to Stock modules.
After rebooting, I used Flash GUI to flash the LK_DNA 0.9.1 boot.img, booted into recovery and then flashed the LK_DNA 0.9.1 modules.
About 30 minutes after reboot, System Tuner showed that all cores were online (and stayed online)
In both instances, I wiped the Dalvik and cache as part of the Flash GUI flash. I'm using the stock ROM (with some apps removed and mods.)
As others have when they've run into this issue, I believe I've done this properly so I don't know what the issue is.
I've since reflashed 2.4.2 boot.img and modules and everything is back to "normal."