We have noticed the same thing. In addition, the CostPerConvertedClick column (which is supposed to be Money, i.e. micros) has changed as well. It used to be like any other Money column, returning micros like 750580000, but now we're seeing things like 0.0 and "750,580,000.0", causing us parsing errors (you can't parse these as longs, which is what our code does).
Thanks,
Greg