Large airspeed fluxuations, but no big change in wind.

I have FSUIPC and AS 2012. I have all the gust suppression, and wind smoothing boxes checked in both programs. I also have turbulence disabled in FSX itself, and I made all the recommended changes in the FSUIPC README document.

I'm getting periodic rapid airspeed losses of about 40 knots at high altitudes, but the indicated wind speed and direction are stable with no appreciable sudden changes.I noticed there are several gust and ramp parameters in the weather section of the FSX.CFG file. Does it help to make changes to any of them? I use a PMDG 747, which I know is suceptible to sudden wind changes,however, others I've talked to say they're

not experiencing the problem when FSUIPC is installed. Any ideas? Thanks.