I know that many with legit copies have had problems but the percentage is very surprising if accurate.

However, 42% of a sample of 137, that sample size as far as statistical analysis is concerned would be considered insufficient to give any accurate result.

With the help of a researcher, I went through a sample of 137 recent problem reports from actual Windows users, posted publicly on the WGA Validation Problems forum. Our research was the online equivalent of listening in to two weeks worth of calls to Microsoft's support lines. The results we found directly contradict Microsoft's insistence that "only a handful of actual false positives have been seen."

Also this sample only comes from those experiencing a problem, which is obviously going to skew and results and there is effectively no control group. 42% of 137 is significant but, this represents an minute percentage of the millions validated overall.