Presonus Firebox vs Creative Audigy

[JSOG]

Hello everybody,

I have recently bought a Presonus Firebox for recording purposes. Everything's going fine until I'm tired of switching cables from computer speakers to headphones.

So I decided to connect my headphones to headphone output on the Audigy and select the sound output on my computer. Problem is, when switching to Audigy in Sound parameters I hear all sorts of glitches and high pitched beeps. My Firebox is hooked to computer through the Firewire port on Audigy.

Is it a compatibility issue with Presonus and Creative? Should I buy a separate Firewire card to plug my Firebox in?

Anyone got an idea?

Thanks in advance

J-S