A8N32-SLI Deluxe (ALC850) AC97 - Popping/clicking sound

I own a A8N32-SLI Deluxe motherboard and in Windows 7 (x86), a popping/clicking noise can be heard before and after any sound is played, be it the Windows Explorer sounds or a mp3 file or video.

The best I can describe it is, the pop/click sounds like it you just turned on an amp, like a surge of electricity to the speakers. I'll try to get a recording of the sound if I can.

I have no such problem with the same motherboard under XP.

This occurs with the drivers Win7 installs through Windows Update (Realtek AC97) but I have tried installing the latest drivers from Realtek's own site (dated 2009/3/36 file name: 6303_Vista_Win7_PG537.zip).

I've also tried installing the Realtek XP drivers (A4.06) but I get an error during installing saying a file is missing, so I presume they're incompatible. I've even tried installing the Realtek HD drivers as a last resort but they're obviously incompatible with this motherboard and don't work.

I tried looking for Nvidia nForce drivers, but the latest one I could find were these 15.23 Vista drivers, however they don't contain audio drivers.

I'm aware that this motherboard has known audio issues particularly with the onboard audio picking up external interference which can be fixed by muting the PC Speaker or just unhooking the wire directly from the motherboard, as noted here and here.

I have already done the above and it has no effect - I'm not getting static, just a click before and after sound is played.

Does anyone have the same motherboard also have the same problem? Does anyone know of a fix?

Thanks for any help.