Yes I've experienced that also. But having the *option* of air support is a really nice feature and it's not something I'd like removed, especially now the AAA assets actually look for it. It does make spotting those pesky guns somewhat easier.
When you had control of your air support you could tell it roughly where to look, and you could cancel it. At present, certainly in the campaign to date, I've had two separate missions where I've been straffed to pieces and had platoons obliterated by massed rocket fire. I've not been able to cancel the missions at all, and because I like to play the slow game, using small squads to recon the area before planning an attack, I suffer lots of friendly fire before I even get started