The Drivers are included on the yellow CD with the Soundmax software which I take it you have installed via CD.
Also did you attach the Audio leads from CD/DVD drives to motherboard, they do not need to be fitted as XP and the Audio Data flow can transfer via Ribbon.
Ok, Did you update the BIOS to v.1013 ? As the motherboard needs this update for Sempron's
Let us know more on the Optical Drives please Make/Model No.
I take it also XP is a Clean Install, if you have changed the motherboard and left your older drivers could be another reason.