Whenever I start FSX, right at the outset, the sound becomes very static as though there is interference. My sound system checks out ok'ey and I am able to experience great sound in every other venue. Also, the motion of the airplane that I happen to be flying at the time also seems to be kind of "herky-jerky".
Quad Core Processor with Nvidia GeForce 8600 GT. Older PC but never had these issues to begin with.
Get a better video card, yours is a little long in the tooth.
It's the main reason that your aircraft is "herky-jerky".
Everything gets old, even me and begins to loose "strength" over time.
As far as the static, don't really know.
Get a good 1-2gig card and see if all clears up.
Let us know how you do.