You are right, the grapic hardware acceleration wasn't the cause of the noises, and they came back.
I've tried lots of things , reinstalling the OS and Scope, even changing the ATI graphic card for a nvidia to try to isolate the graphic IRQ...with no more result on this part.
Now I'm trying touse Samplitude, I've discovered that only Ableton Live was making clips ans pops. So now I'll try to learn Samplitude (It looks much more interesting).
In the same time, I exchanged the plates of my pulsar and scope cards, to get the zlink plate with ADAT on the biggest Scope card (I got 2Pulsar2 and 1 Scope).
Tha IO were shared on the pulsar (zlink for a16ultra) and Scope (ADAT from the octopre). I changed it to match Adat and Zlink on the same plate, and leave the pulsar plate without IO connections (I read that it can avoid phase problem and too much stdm connections).
After that, I had new errors from Scope when loading my old projects cause bad IO (I presume...)
I rebuild them (except for the STM4896) and since that it looks ok for working.
I got a last problem, now when I close Samplitude or open (and Ableton too), I always have a PCI capacity limit. The cards can't work well after retry, and sometimes retry don"t work at all. I must resync the samplerate to make it work again.
I've tried to reinstall Scope and Samplitude, but same result.
Do you know if I can try to avoid this message please ?
Edit: I just made a new samplitude project from blank, and it makes the PCI Limit again. It looks like a reaction when opening or closing the sequencer.