Normal Factory Cable Process Does Not Work topic

I have searched and read a bunch and have not stumbled upon my situation.
Hopefully someone can shed some light on my use of a factory cable.
Bought a cable from SkOrPn - great guy and very helpful. We thought maybe the problem was the cable so he sent out another. TO BE CLEAR, ISSUE IS NOT WITH SkOrPn's CABLE. Both cables yield the same results.
So, here's the deal:
I have 2 KFs that where bone stock. I used KFU to root, install TWRP and FFF 1.5 Bootloader. All worked fine and I subsequently installed CM11. So all is good.
Now when I try to use the Factory Cable as instructed

Quote:

Factory cable - Using a factory cable is the most straightforward method of enabling fastboot mode on the Kindle Fire and it will work with any bootloader. With the device off, plug the cable into the Kindle Fire, then the computer and the device will boot up directly into fastboot mode. No other user intervention is required.

But when I plug the Fcable into the fire it immediately powers on and boots normally, skipping fastboot mode. This happens with or without plugging the other end into the PC.
So SkOrPn suggested I try plugging into the PC 1st and then the fire. This does boot to fastboot mode. So now I unplug the Fcable and using a "normal" cable plug the fire back into my PC. Now I get an error message saying that the USB device cannot be installed and of course KFU/ADB/fastboot does not recognize my device. So I am (or appear to be) in fastboot mode, but can't communicate with my fire. Keep in mind I have KFU working, so I know drivers are installed.
Any thoughts?
And the above is the same for BOTH fires.

Luckly I am fully rooted with FFF 1.5 and CM11, so I really dont need to use the factory cable. But I would like to figure this out BEFORE I need it!