I used to have an Audigy 2 and ended up getting rid of it. Audigy seems to have a big problem with IRQ sharing. I know on my computer if the Audigy was running on an IRQ shared with something else I would get a lot of crackle in the speakers. It was not the speakers but the sound coming from the card. Moving it to an unshared IRQ lessened it but even if it was shared with a USB hub or the USB ports themselves it caused problems.

I bought a $30.00 sound card from Compusa - problems went away and while its not as great in sound quality it ALWAYS works.

My problems with my Audigy though were long before FS One so I have no experience using it with FS One.