Seems C1E bug is squashed.
Awesome job, whoever killed the C1E bug that had been preventing my BIOS from having it enabled.
Couple days ago I installed the latest nightly on my box.
Box is an Athlon II 255, asus m4a89gtd usb 3 motherboard (AMD 890GX). C1E enabled made Haiku reboot previously while the OS was initializing.
Coupled with proper Radeon support (4290 onboard IGP) full-time Haiku use just went up a few more notches.