Simy -

The beeping is coming from the variometer. We just added an FAQ item about this:

http://www.inertiasoft.com/fsonefaq/#Q1047-FS1

We have had sound issues w/ the Audigy card, and there's an FAQ on that here:

http://www.inertiasoft.com/fsonefaq/#Q1014-FS1

We have not heard of issues w/ the Realtek AC97.

Some people have solved the problem by updating the sound card driver. This approach might work in your case.

Let me know if any of this helps.

Michael