in my case,
i changed motherboard cause of problems running 3 cards, i still have that motherboard , but just Luna II installed, so no problems with that,
i had problems running 3 cards, even the chipset is the same, cpu slot, almost identical, just other company and problems gonne away,
I had problems with Asus P4C800Deluxe and Intel 865PERL (don't have it anymore), running 3 cards (2 x Pulsar XTC and Luna II), tried everything possible,
after using Scope platform with Cubase, sequencer soon stops and everything freezes, sometimes blue screen appears when using with Modular in Scope,
i guess i had luck, cause then i bought another motherboard Abit IC7 (the same chipset like Asus) and after then works really nice,
i do have that computer with 3 cards just for making music, no internet connection (cards), a lot of services disabled, no other cards installed, really raw setup,
Winxp, Standard PC mode, every card on different IRQ, Scope 4.5 ...
i'm sure every setup is different and my problems could or could not help to other users, but like i said, other motherboard makes my music setup very solid, so i can
make music and not repairing windows and similar
sometimes i get error messages like DSP optimization or similar, but that only happens if i add large modules into scope project and depends which ones, but after doing optimization or just restaring Scope helps and i can load modules in DSP meter to the end ...
matej