nvidia - MSI GS60-GTX965 - Unable to get Bumblebee to run properly - Could not load GPU drivers

I installed Ubuntu 14.10 on my new laptop and while everything works great (save for the wifi card but that's a completely different matter) I'm having some trouble getting Bumblebee to run.

I followed the guide on this thread to install it and everything seemed to be well but when I try to test it out running optirun glxsheres I get the following error message:

[ 1465.129240] [ERROR]Cannot access secondary GPU - error: Could not load GPU driver
[ 1465.129265] [ERROR]Aborting because fallback start is disabled.

I know there are an awful lot of threads about this error and I went through several (specially this one and 3 others but I lack the reputation to post the links xD) trying out the solutions posted there to no luck.

Some hardware info:

00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06) (prog-if 00 [VGA controller])
    Subsystem: Micro-Star International Co., Ltd. [MSI] Device 1102

    Flags: bus master, fast devsel, latency 0, IRQ 46
    Memory at f6400000 (64-bit, non-prefetchable) [size=4M]
    Memory at d0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at f000 [size=64]
    Expansion ROM at  [disabled]
    Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
    Capabilities: [d0] Power Management version 2
    Capabilities: [a4] PCI Advanced Features
    Kernel driver in use: i915

01:00.0 3D controller: NVIDIA Corporation Device 13d9 (rev a1)
    Subsystem: Micro-Star International Co., Ltd. [MSI] Device 1102
    Flags: bus master, fast devsel, latency 0, IRQ 16
    Memory at f5000000 (32-bit, non-prefetchable) [size=16M]
    Memory at e0000000 (64-bit, prefetchable) [size=256M]
    Memory at f0000000 (64-bit, prefetchable) [size=32M]
    I/O ports at e000 [size=128]

    Expansion ROM at f6000000 [disabled] [size=512K]
    Capabilities: [60] Power Management version 3
    Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
    Capabilities: [78] Express Endpoint, MSI 00
    Capabilities: [100] Virtual Channel
    Capabilities: [250] Latency Tolerance Reporting
    Capabilities: [258] L1 PM Substates
    Capabilities: [128] Power Budgeting 
    Capabilities: [420] Advanced Error Reporting
    Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 

    Capabilities: [900] #19

Not sure if it's okay or not but shouldn't the exact nvidia model be displayed there? GTX 965.

Any idea/input/whatever that I could try? Thanks. Dunno what info might be needed so just ask.

Edit: Updating some info after my latest attempt to make everything run.

With lspci -v | less:

01:00.0 3D controller: NVIDIA Corporation Device 13d9 (rev ff) (prog-if ff)
        !!! Unknown header type 7f

I'm pretty sure that's not good but I installed Witched 2 through steam, set it to run using primusrun and I see the LED indicator on the laptop switch to indicate the dedicated VGA being in use and the game seems to run as smoothly as I can expect such a heavy game to run with everything set to ultra.

The standard Ubuntu NVidia drivers generate some problems on slightly older and slightly newer NVidia hardware.

If you want more then the standard Ubuntu repository drivers, install the xorg.edgers PPA. As the xorg.edgers group ask not to give installation instructions directly without linking to their page, this is the best I can do for now...

If you don't know what a PPA is or need some guidance about rolling forward and backward of driver versions after reading their page, leave a comment below.