guess i spoke too soon, the audio crackling thru presonus firestudio project started again, just like before, almost constant crackling! I switched realtek onboard audio in bios on, now the audio is better thru presonus audio card.
Win7 64bit OSX SnowLeo and
i7-920 / 8GB RAM /ASUS P6T/ e-GeForce 7200GS graphics
-Cubase 6.5 -RME Babyface -Presonus StudioLive -M-audio ProFire 610 Yamaha NS-10M,ADAM A7X, AT ATH-m50. -AKG c414bxls, Neumann TLM103, Blue Bluebird, Rode NT1-A, Shure SM7b, Sm57 3x, Sm81, sm58, senn. e838