Wind Problem

I hope someone can help with this problem.Whenever I have squawkbox open, it shows a headwind. Even throughout a 360 deg. turn there will be a headwind. It usually is about 50kts, but is often around 200kts & has been up to 500kts.The winds in my flightsim & FS Navigator are correct & it appears that the aircraft flies according to these winds. However, ATC & servinfo seem to get their info from the squawkbox readings. Consequently, I often have controllers asking me if there's a problem or to speed up.I do use FS Meteo, but I've tried it without it enabled & with the 'clear all weather' option on, but there is still a headwind. I've also reinstalled SB & flightsim & I've even reformatted my hardrive, but the problem still persists.Any help will be appreciated