No, discrimination against atheists is not just a problem that happens in "a few Islamic countries". In Arkansas, Mississippi, North Carolina, South Carolina, and Tennessee, atheists are not allowed to hold office. This is only the official policy. In everyday life, people are bigoted against atheists. It's a real problem.
I remember seeing a poll that concluded that atheists were the least trusted group in the US, ranking even below Muslims. While the "discrimination" exhibited here in the Bible Belt is not of the degree that Cadet speaks of in Islamic countries (death) it is real nonetheless. Anyone who depends on the patronage of the community for a living would be foolish to come out of the faith closet because the likely result would be to see a significant and immediate decline in their livelihood . All you have to do to confirm this is to read a few threads on national websites dealing with the right of Christian owned businesses to refuse services to gays, or Miuslims. For this reason, I believe a large number of non-believers go thru the motions of the faith they probably grew up in, and never admit to those around them that they are no longer believers. I know from experience.
While atheists are discriminated against (I'm not going to lie), it is not wide spread across the globe. Discrimination and persecution of atheists only happens in a few Islamic countries (19, 13 punishable by death) in the middle east and in north Africa. Compared to the PERSECUTION of Christians, it really isn't a big issue (not saying that discrimination is ok)