Timo,
More recent tests have found this to be only with certain setups and certain sequencers, cubase sx and nuendo mainly.
I know of a few people (if only a handful) now running nf4 single cpu boards and not having these problems.
One thing to point out these initial nf4 problems did and do NOT affect any current dual cpu nf4 boards. I have tested two extensively myself (Tyan K8WE and SuperMicro H8DCE) and they perform amazingly.
I agree though, If you want total hassle free setup and can find a decent nf3 board that will support a dualcore X2 it just might be the way to go....or go for a nice dualie like me
second hand opterons go CHEAP on ebay.
ten