Can't Burn Rewritables

Hello,

I have a problem with my DVD-burner that has always worked well,
apart from the fact it wouldn't succeed in burning Dual-Layers.
But then I found that apparently it wasn't successful all together, so I'm fine with that.

The problem now is that I can't burn Rewritables.
I don't know where to exactly start to explain, because quite random things happen.
Like for example, I want to burn some files to a brand new Rewritable DVD.
Usually it just goes ahead and burns, but for example Nero fails to verify it.
Then I format it again and for example both Nero and Ashampoo say it's not an empty disc anymore.
I also tried it with Alcohol, first creating an image of the files though,
but then burning that image, which it says it succeeds to.
However, when I check to see if there's anything on it, any computer says it's empty.
I can't use any of these DVDs anymore until (I think) when I restart the computer.

So has anyone heard of this issue and how can I fix it?
I never changed anything about the system besides the motherboard one time.
But I just let it install all hardware automatically like I did with the previous one.
Updating it... I don't know how exactly.
I've looked for Firmware but on the official website I can find a model with almost the same name,
but then it misses one letter, so I don't know if that matters.


Also, apparently it does simply burn finalized CDs and DVDs.
You know, audio-albums, movies, things like that don't seem to be a problem.
It also plays about anything, but I CAN NOT create backups to Rewritables.
I guess I could use a pile of Writables, but I already know I want to revise them.
So I'd only end up with outdated copies I wouldn't use anyway.