Guild Wars won't mute audio when in background

I have the option selected to mute GW audio while in background, but it never actually works. I tab out into another program, and the GW sounds are still playing like they normally do. Is this a known bug or is it due to my sound hardware (highly doubtful)?

You actually have to minimize GW, tabbing out doesnt work. No idea why but the same thing happens to me.

Oh, ok. That's an easy fix. I guess they coded that game function to only work when using the in game minimize button instead of recognizing when GW is minimized in the OS. Thank you.

Not true, it works for me as it`s supposed to. I don`t minimize GW, I just go from full screen to windowed mode - say for example, while looking something up on wiki. If I have it checked, there`s no sound, if I have it un-checked, there is sound.
I have no solution for you though.

Do you minimize GW after you enter windowed mode? The background audio mute option works in that scenario for me as well. I guess they just didn't make it work for alt-tabbing.

Don't alt+tab out, you will still hear sounds.
Just click the minimize button on the top right-hand corner.

Yup, doesn't always work for me either if I alt-tab out the game. As jiggles said you have to minimize for it to really work.