Windows 10 and Saffire Firewire issues

This may be of help.
For the last year all has been well running Windows 10 with the legacy 1394 drivers. Two weeks ago I had a windows update and I started to suffer constant drop-outs - the FW Active light would just turn off. Trust me, I uninstalled and reinstalled many things - even the nVidia display drivers - but the problem remained.
In desperation I switched to the old VIA 1394 driver in my Windows 10 list and, after 24 hours, everything is still working. (I tried this driver when I had the same problem after a Windows update a year ago. Back then it didn't help - most odd).
I am not looking forward to the next Windows update.
OK so than idea failed shortly after I posted my comment. However, having installed the VIA drivers and then going back to the legacy drivers I have managed 4 hours editing im Adobe Premiere without a single drop-out.
...but not for long.

However, everything is now working again after I made two changes. Unfortunately I cannot say which one fixed the problem - very sloppy work for a professional tester but I was fed up with the whole thing and just wanted to fix it.

1. I took the Firewire card out and cleaned the dust and fluff from the other two ports.

2. I put the card into a different slot in my PC. When I looked at the system settings in Windows 10 I could see that the USB controller items that it was sharing an IRQ with had changed (so it was now sharing with different hardware).

I am back with the legacy driver, a clean card and different shared IRQ and it's all working well.