This is getting annoying, and worse!
I had a recurrent problem since switching to W7 64bit where when I tried to change my MR Editor preset my PC would appear to freeze until I hit C+A+D when, without having to do anything more, it would spring back to life.
I called Steinberg technical support and it appeared the problem was down to the Yamaha Steinberg FW Bus having TWO entires under Device Manager. Removing one seemed to solve the problem.
Now, since updating to v1.70 drivers, this issue has extended itself to regular BSODs - at least one a day, often two or more! According to my logs, every time it’s due to the Yamaha Steinberg FW Bus driver.
In the process of trying to fix this, and noticed the double-driver is back. Uninstalled ABSOLUTELY EVERYTHING, restarted, reinstalled, restarted … the double driver is back! Every time I restart, I get TWO Yamaha Steinberg FW Bus drivers appearing in Device Manager, and serious problems as a result.
Can anyone suggest anything?
Apart from reinstalling Windows? I’m NOT reinstalling Windows! 
Aha!
Looking closer at them, it appears that one is ‘on’ my Ti chipset card, and the other is ‘on’ my Legacy firewire driver.
I’m going to disable the onboard FW on my PC and see what happens.
Onboard FW was already disabled!?!
So at the moment in Device Manager I have
IEE1394 Bus host controllers
|- 1394 OHCI Compliant Host Controller (this was (legacy) but after uninstalling it has reappeared in this non-legacy version)
|- Texas Instruments 1394 OHCI Compliant Host Controller
Sound, video and game controllers
|- Assorted audio devices such as blackmagic, soundblaster, xbox controller, midi etc
|- Steinberg MR816 Series
|- Yamaha Steinberg FW Bus
|- Yamaha Steinberg FW Bus
|- Yamaha Steinberg FW WDM Audio
Under the properties of the two Yamaha Steinberg FW Bus entires, under ‘Location’ each lists one of the two FW Bus host controllers.
If I uninstall the non-Ti entry, one of the FW bus entries disappears, but the MR816 stops working. When I restart my PC, it reappears.
My computer still freezes when I change an MR Editor preset, and I’m still getting BSODs.
Can anyone help?
I’ll forward a copy of the contents of this thread onto Steinberg Support.