I can't remember what kind of error I got. I can check for tomorrow, I am at school now. Don't know what chipset is, but I doubt it has anything to do with this. I have XP and 512 Mb RAM. Did that help?
In order to use 'em both at the same time, you must "share" the audio driver. In SONAR, go Options --> Audio... --> Advanced tab, and check the "Share driver with other programs".