Before I spend hours (very possibly!) tracking down the cause and cure, I wonder if anyone is able to give me some leads here?I run FS9(.1) on the machine specified in the profile below - and it runs beautifully, even at high settings and a resolution of 1920x1200. The one consistent problem is that I get noise interference in the form of frequent, short (but quite loud) simultaneous 'squeaks' and clicks every few seconds. Sometimes everything is fine, but at least 75% of the time I get this annoying interference. Frame rates and everything else seem to be running fine. Very hard for me to find a common factor - it's not just with one plane or one sound file or whatever, as far as I can see. It happens whether engines are running or not - and whether I have the Audigy PC card connected or not too. Memory seems fine when I log it during a flight - plenty of free RAM.I am not sure where to start troubleshooting this one, so advice very welcome.Thanks,Martin

Hi Martin,Suggestion: Reduce directx sound accelleration in dxdiag (start, run, DXDIAG, sound tab, move slider to the left a notch or two). This is a known fix for some users but usually effecting only those with built-in cheap sound boards. Surprised to see the SB Audigy having this problem! Might be worth a try though...Best,

OK, given that a go, thanks, but it doesn't reduce the frequency of the 'bleeps'. That said, I am hardly getting any interference at all at the moment - a little beep once a minute ir so. I will have to try to track down what it is - scenery, plane, weather, or whatever, that is causing the problem..Meanwhile, I will have to imagine that the little clicks and beeps are 'radio interference'!!M.