The problem, I think, is that normally when one sees IQ and race spoken of together, it is to denigrate a race(s) based on IQ scores.
Of course, IQ is not a strong measurement of intelligence (something which tends to be vaguely defined, at best). A person can get a different score on IQ tests for a variety of reasons: mood, physical health, education levels, etc. IQ tests are really more a measurement of certain abilities. There's also the "Flynn effect," which another poster provided a link for in another thread: basically, IQs have been rising (in the US and other nations) at a rate which seems too fast to be accounted for simply by genetic changes.
Just what IQ tests actually measure, how accurate they are with whatever it is they actually measure, and even just what constitutes intelligence are all subjects still only somewhat understood or very much open to debate. Trying to draw conclusions about race from testing which has such issues is problematic, at best.