Now im not one to talk as I have not updated to 5.6 yet. (I have installed 10.5.6 on a laptop temporarily) Is it possible that a few of your kexts got overwritten with those from the update? Id try rolling back a few of them if you backed them up.

---

MOBO: Z77MX-QUO-AOS CPU: Core i7 3770K GPU: MSI N760 TF 2GD5/OC Case: Modded MacPro2,1
Memory: 32GB Corsair Vengeance (CMY32GX3M4A1600C9) Wifi: Airport Extreme bcm94321MCA BIOS: HermitCrab Labs H3A.816M
Monitor: AOC Q2963Pm 29" WFHD 2560x1080 21:9
Interests: KDE on Apple Darwin, Keeping it real with the command line, Helping those that help themselves