@ samsamo: Dude, this sounds horrible, I know - if been down that road too! But keep your head up, I am almost certain there is a solution, since many here on the board use the exact same combination!
So let's go at it:
- how is your DM3200 connected to your computer (onboard Firewire connection? If so, brand of the board / dedicated Firewire-card? If so, which one?
- Did you recently update Win10?
- Did you update your mainboard, graphics card or firewire drivers?
- Changed settings at BIOS level?
In any case: do you have the possibility to return to a previous state of your system prior to the day the difficulites appeard?
Also: please post your firmware version of the DM3200 AND the driver version of your IF-FW DM MKII! Only recently Microsoft got rid of some drivers for legacy hardware - driver 176851 is running rock solid on my Win 10 Pro. AFAIK it is the latest and is ever sinced labeled as "beta" - but as I said: it's doing absolutely fine! Definitively go for this one.
Also check your firewire cable! If there is some damage to it, your DM3200 would still state the card as "OK" (because the card would be), but the real evil would be a broken cable. Maybe check this one first!
Good luck,
snafu