UX32VD - Kernel 3.13.0 - Refused to change power state

I have issues with bbswitch 0.8 on my laptop.

For reference: posted this issue earlier today: https://github.com/Bumblebee-Project/Bumblebee/issues/532

I was recommended to upgrade bbswitch. This causes different behavior when the module attempts to disable the card. Dmesg output:

[   14.435156] bbswitch: detected an Optimus _DSM function
[   14.435165] bbswitch: Succesfully loaded. Discrete card 0000:01:00.0 is on
<removed non-relevant output>
[  100.164725] bbswitch: disabling discrete graphics
[  100.164736] ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20131115/nsarguments-95)
[  100.177196] pci 0000:01:00.0: Refused to change power state, currently in D0

Seems the card refuses to change state. When I try to run optirun glxgears:

[  114.520342] bbswitch: enabling discrete graphics
[  114.978921] NVRM: loading NVIDIA UNIX x86_64 Kernel Module  319.82  Mon Dec 30 02:18:32 PST 2013
[  115.293555] vgaarb: this pci device is not a vga device
[  115.300257] NVRM: failed to copy vbios to system memory.
[  115.302136] NVRM: RmInitAdapter failed! (0x30:0xffffffff:711)
[  115.302142] NVRM: rm_init_adapter(0) failed

Notes:

The vgaarb message doesn't show with a kernel patch which I have tried, but not the issue in overall.
The nvidia driver doesn't compile for kernel 3.13.0 - an ACPI function symbol was not exported. I patched this myself simply be putting the symbol in the EXPORT_SYMBOL(symbol) macro.
Nouveau doesn't seem to support my card.

I'll be happy to do some debugging with the devs, since I struggled so much with this now I no longer know where to look.

modinfo bbswitch
filename:       /lib/modules/3.13.0/misc/bbswitch/bbswitch.ko
version:        0.8
author:         Peter Wu <lekensteyn@gmail.com>
description:    Toggle the discrete graphics card
license:        GPL
srcversion:     90CDB6EFB3C4142AB1E1E16
depends:        
vermagic:       3.13.0 SMP mod_unload modversions 
parm:           load_state:Initial card state (0 = off, 1 = on, -1 = unchanged) (int)
parm:           unload_state:Card state on unload (0 = off, 1 = on, -1 = unchanged) (int)
parm:           skip_optimus_dsm:Skip probe of Optimus discrete DSM (default = false) (bool)

Bumblebee-Project / bbswitch

UX32VD - Kernel 3.13.0 - Refused to change power state #86